/* Problem URL: https://codeforces.com/gym/103388/problem/C */

#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 (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;
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    ll b;
    int l;
    cin >> b >> l;

    ll mod = b + 1;

    auto fastpow = [&](ll a, ll p) {
        ll ans = 1;
        ll now = a;

        rep(i, 20) {
            if ((p >> i) & 1) {
                ans *= now;
                ans %= mod;
            }

            now *= now;
            now %= mod;
        }

        return ans;
    };

    vl fds(l);
    cin >> fds;

    ll now = 0;
    rep(i, l) {
        now += fds[i] * fastpow(b, l - i - 1);
        now %= mod;
    }

    if (now == 0) {
        cout << "0 0\n";
        return 0;
    }

    rep(i, l) {
        ll p = fastpow(b, l - i - 1);
        ll tmp = (p * now) % mod;

        if (fds[i] >= tmp) {
            cout << i + 1 << ' ' << fds[i] - tmp << '\n';
            return 0;
        }
    }

    cout << "-1 -1\n";
}