#include <bits/stdc++.h>
using namespace std;
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define REP(i, n) FOR(i,0,n)

int main() {
    cin.tie(nullptr), ios::sync_with_stdio(false);
    int N, Q;
    string S;
    cin >> N >> Q >> S;

    constexpr int D = 26;
    vector cnt(D, vector<int>(N + 1));
    REP(i, N) {
        int d = S[i] - 'a';
        REP(e, D) cnt[e][i + 1] = cnt[e][i] + (d == e);
    }
    while (Q--) {
        int l, r, x;
        cin >> l >> r >> x;
        l--;
        REP(a, D) {
            auto ox = x;
            x -= cnt[a][r] - cnt[a][l];
            if (ox > 0 and x <= 0) cout << (char)('a' + a) << '\n';
        }
    }
}