#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, s, e) for (int i = (int)(s); i < (int)(e); ++i)

int main() {
	cin.tie(nullptr);
	ios_base::sync_with_stdio(false);
	
	int N, Q;
	string S;
	cin >> N >> Q >> S;
	
	vector sum(N, vector<int>(26));
	rep(i, 0, N) sum[i][S[i] - 'a'] = 1;
	
	rep(i, 1, N) rep(j, 0, 26) sum[i][j] += sum[i - 1][j];
	
	rep(query, 0, Q) {
		int L, R, X;
		cin >> L >> R >> X;
		--L, --R;
		
		int cnt = 0;
		rep(j, 0, 26) {
			cnt += sum[R][j] - (L == 0 ? 0 : sum[L - 1][j]);
			if (cnt >= X) {
				cout << (char)('a' + j) << '\n';
				break;
			}
		}
	}
}