diff --git a/.gitignore b/.gitignore
index 378eac2..cddf16a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,4 @@
-build
+*
+!*/
+!*.cpp
+!.gitignore
diff --git a/2017/phase3/arranhaceu.cpp b/2017/phase3/arranhaceu.cpp
new file mode 100644
index 0000000..a38e9b3
--- /dev/null
+++ b/2017/phase3/arranhaceu.cpp
@@ -0,0 +1,117 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (size_t i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (size_t 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;
+}
+
+void add(int i, int v, vl &bit)
+{
+    for (; i < bit.size(); i += (i & -i)) {
+        bit[i] += v;
+    }
+}
+
+ll sum(int i, vl &bit)
+{
+    ll sum = 0;
+    for (; i > 0; i -= (i & -i)) {
+        sum += bit[i];
+    }
+    return sum;
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int n, q;
+    cin >> n >> q;
+
+    vl a(n);
+    vl bit(n + 1, 0);
+    cin >> a;
+    for (size_t i = 0; i < n; i++) {
+        add(i + 1, a[i], bit);
+    }
+
+    while (q--) {
+        int c;
+        cin >> c;
+        if (c) {
+            int k;
+            cin >> k;
+            cout << sum(k, bit) << '\n';
+        } else {
+            int i, v;
+            cin >> i >> v;
+            int prev = a[i - 1];
+            a[i - 1] = v;
+            add(i, v, bit);
+            add(i, -prev, bit);
+        }
+    }
+}
diff --git a/phase3/2021/falha.cpp b/2021/phase3/falha.cpp
similarity index 100%
rename from phase3/2021/falha.cpp
rename to 2021/phase3/falha.cpp
diff --git a/phase3/2021/ogro.cpp b/2021/phase3/ogro.cpp
similarity index 100%
rename from phase3/2021/ogro.cpp
rename to 2021/phase3/ogro.cpp
diff --git a/phase3/2021/teclado.cpp b/2021/phase3/teclado.cpp
similarity index 100%
rename from phase3/2021/teclado.cpp
rename to 2021/phase3/teclado.cpp