diff --git a/Codeforces Round 969 (Div. 1)/A. Iris and Game on the Tree.cpp b/Codeforces Round 969 (Div. 1)/A. Iris and Game on the Tree.cpp
new file mode 100644
index 0000000..46c059c
--- /dev/null
+++ b/Codeforces Round 969 (Div. 1)/A. Iris and Game on the Tree.cpp	
@@ -0,0 +1,154 @@
+/* Problem URL: https://codeforces.com/problemset/problem/2006/A */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    cin >> n;
+    vvi graph(n);
+    rep(i, n - 1) {
+        int a, b;
+        cin >> a >> b;
+        a--, b--;
+        graph[a].push_back(b);
+        graph[b].push_back(a);
+    }
+
+    string a;
+    cin >> a;
+
+    array<int, 3> c = {0, 0, 0};
+    int ch = 0;
+
+    function<void(int, int)> dfs = [&](int i, int p) {
+        if (i != p && graph[i].size() == 1) {
+            if (a[i] == '?') {
+                c[2]++;
+                return;
+            }
+
+            c[a[i] - '0']++;
+            return;
+        }
+
+        if (a[i] == '?') {
+            ch++;
+        }
+
+        repv(j, graph[i]) {
+            if (j == p) {
+                continue;
+            }
+            dfs(j, i);
+        }
+    };
+
+    dfs(0, 0);
+
+    if (a[0] == '?') {
+        cout << max(max(c[0], c[1]) + c[2] / 2, min(c[0], c[1]) + (c[2] + (~ch & 1)) / 2) << '\n';
+        return;
+    }
+
+    int t = a[0] - '0';
+    cout << c[t^1] + (c[2] + 1) / 2 << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}
diff --git a/European Championship 2025 - Online Mirror (Unrated, ICPC Rules, Teams Preferred)/F. Mascot Naming.cpp b/European Championship 2025 - Online Mirror (Unrated, ICPC Rules, Teams Preferred)/F. Mascot Naming.cpp
new file mode 100644
index 0000000..0fd2371
--- /dev/null
+++ b/European Championship 2025 - Online Mirror (Unrated, ICPC Rules, Teams Preferred)/F. Mascot Naming.cpp	
@@ -0,0 +1,175 @@
+/* Problem URL: https://codeforces.com/problemset/problem/2068/F */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 0
+
+void solve()
+{
+    int n;
+    cin >> n;
+    V<string> a(n);
+    cin >> a;
+
+    string s;
+    cin >> s;
+
+    auto issub = [&](string &a, string &b) {
+        int i = 0;
+        rep(j, a.size()) {
+            if (a[j] == b[i]) {
+                i++;
+                if (i == b.size()) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    };
+
+    vvi pos(26);
+    vi ind(n);
+
+    rep(i, n) {
+        if (issub(a[i], s)) {
+            cout << "NO\n";
+            return;
+        }
+
+        pos[a[i][0] - 'a'].push_back(i);
+    }
+
+    cout << "YES\n";
+
+    string ans;
+
+    auto prall = [&](int j) {
+        vi tmp;
+        swap(tmp, pos[j]);
+        ans.push_back(j + 'a');
+
+        while (!tmp.empty()) {
+            int i = tmp.back();
+            tmp.pop_back();
+            ind[i]++;
+            if (ind[i] < a[i].size()) {
+                pos[a[i][ind[i]] - 'a'].push_back(i);
+            }
+        }
+    };
+
+    repv(now, s) {
+        int inv = now - 'a';
+        rep(j, 26) {
+            if (j == inv || pos[j].empty()) {
+                continue;
+            }
+
+            prall(j);
+            j = -1;
+        }
+
+        if (!pos[inv].empty()) {
+            prall(inv);
+        }
+    }
+
+    cout << ans << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}
diff --git a/Good Bye 2024: 2025 is NEAR/C. Bewitching Stargazer.cpp b/Good Bye 2024: 2025 is NEAR/C. Bewitching Stargazer.cpp
new file mode 100644
index 0000000..9157e90
--- /dev/null
+++ b/Good Bye 2024: 2025 is NEAR/C. Bewitching Stargazer.cpp	
@@ -0,0 +1,124 @@
+/* Problem URL: https://codeforces.com/problemset/problem/2053/C */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    ll n, k;
+    cin >> n >> k;
+
+    function<pair<ll, ll>(ll, ll)> func = [&](ll l, ll r) -> pair<ll, ll> {
+        ll sz = r - l + 1;
+        if (sz < k) {
+            return {0, 0};
+        }
+
+        ll mid = (l + r) >> 1;
+        if (sz & 1) {
+            auto [an, c] = func(l, mid - 1);
+            return {an * 2 + mid * (c + 1), c * 2 + 1};
+        }
+        auto [an, c] = func(l, mid);
+        return {an * 2  + mid * c, c * 2};
+    };
+
+    cout << func(1, n).first << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}
diff --git a/Polynomial Round 2022 (Div. 1 + Div. 2, Rated, Prizes!)/C. Ice and Fire.cpp b/Polynomial Round 2022 (Div. 1 + Div. 2, Rated, Prizes!)/C. Ice and Fire.cpp
new file mode 100644
index 0000000..659d0ea
--- /dev/null
+++ b/Polynomial Round 2022 (Div. 1 + Div. 2, Rated, Prizes!)/C. Ice and Fire.cpp	
@@ -0,0 +1,120 @@
+/* Problem URL: https://codeforces.com/problemset/problem/1774/C */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    cin >> n;
+    string s;
+    cin >> s;
+
+    int cur = 1;
+    cout << "1";
+    nrep(i, 1, n - 1) {
+        if (s[i] != s[i - 1]) {
+            cur = (i + 1);
+        }
+
+        cout << ' ' << cur;
+    }
+    cout << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}