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

typedef long long ll;
//typedef modint1000000007 mint;
const int MOD = 1000000007;
#define all(x) x.begin(), x.end()
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
const int inf = 1 << 30;
const ll INF = 1LL << 60;
const int dx[8] = {1, 0, -1, 0, -1, -1, 1, 1};
const int dy[8] = {0, 1, 0, -1, -1, 1, -1, 1};
template <class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template <class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }

int main(){
    int n, q;
    string s;
    cin >> n >> q >> s;

    vector<vector<int>> vec(26, vector<int>(n + 1, 0));
    rep(i, 26) rep(j, n){
        vec[i][j + 1] += vec[i][j];
        if(s[j] == 'a' + i) vec[i][j + 1]++;
    }

    rep(i, q){
        int l, r, x;
        cin >> l >> r >> x;
        int cnt = 0;
        int j = -1;
        while(cnt < x && j < 26){
            j++;
            cnt += vec[j][r] - vec[j][l - 1];
        }
        cout << (char)('a' + j) << endl;
    }

    return 0;
}