#pragma GCC optimize ("O2")
#pragma GCC target ("avx2")
#include<bits/stdc++.h>
//#include<atcoder/all>
//using namespace atcoder;

using namespace std;
typedef long long ll;
#define rep(i, n) for(int i = 0; i < (n); i++)
#define rep1(i, n) for(int i = 1; i <= (n); i++)
#define co(x) cout << (x) << "\n"
#define cosp(x) cout << (x) << " "
#define ce(x) cerr << (x) << "\n"
#define cesp(x) cerr << (x) << " "
#define pb push_back
#define mp make_pair
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define Would
#define you
#define please

char pre[10000][10000];

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);


	int N, Q;
	cin >> N >> Q;
	string S;
	cin >> S;
	
	rep(i, Q) {
		int L, R, X;
		cin >> L >> R >> X;

		char c1 = 'a' - 1, c2 = 'z' + 1;
		while (c1 + 1 < c2) {
			char wj = (c1 + c2) / 2;

			int kazu = 0;
			for (int j = L - 1; j <= R - 1; j++) if (S[j] <= wj) kazu++;

			if (kazu < X) c1 = wj;
			else c2 = wj;
		}

		co(c2);
	}


	Would you please return 0;
}