#include <bits/stdc++.h>
using namespace std;

void fast_io() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
}
int sig = 26;

int main() {
	fast_io();
	int n, q;
	cin >> n >> q;
	string s;
	cin >> s;
	int cnt[n + 1][sig] = {};
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < sig; j++) {
			cnt[i + 1][j] = cnt[i][j];
		}
		cnt[i + 1][s[i] - 'a']++;
	}
	for (; q--;) {
		int l, r, x;
		cin >> l >> r >> x;
		l--;
		char ans = 'a';
		int cur = 0;
		for (int i = 0; i < sig; i++) {
			cur += cnt[r][i] - cnt[l][i];
			if (cur >= x) {
				ans = i + 'a';
				break;
			}
		}
		cout << ans << "\n";
	}
}