#include "bits/stdc++.h"
//#define int long long
using namespace std;
using ll = long long;
using P = pair<ll, ll>;
const ll INF = (1LL << 61);
ll mod = 1000000007;


signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	ll N, Q; cin >> N >> Q;
	string S; cin >> S;
	vector<vector<ll>>sum(26, vector<ll>(N + 1));
	for (int i = 0; i < 26; i++) {
		for (int j = 0; j < N; j++) {
			sum[i][j + 1] = sum[i][j];
			if (S[j] - 'a' == i)sum[i][j + 1]++;
		}
	}
	for (int _ = 0; _ < Q; _++) {
		ll L, R, X; cin >> L >> R >> X; L--;
		ll t = 0;
		for (int i = 0; i < 26; i++) {
			ll now = sum[i][R] - sum[i][L];
			t += now;
			if (t >= X) {
				cout << (char)('a' + i) << endl;
				break;
			}
		}
	}
	return 0;
}