#include <iostream>
#include <vector>
#include <string>
using namespace std;

int main(){
    int n, q;
    cin >> n >> q;
    string s;
    cin >> s;
    vector<int> l(q), r(q), x(q);
    for(int i = 0; i < q; i++) cin >> l[i] >> r[i] >> x[i];

    vector<vector<int>> memo(n+2, vector<int>(26, 0));
    for(int i = 0; i < n; i++){
        memo[i+1][s[i]-'a']++;
        for(int j = 0; j < 26; j++) memo[i+2][j] = memo[i+1][j];
    }

    vector<int> usememo(26, 0);
    for(int t = 0; t < q; t++){
        for(int i = 0; i < 26; i++){
            usememo[i] = memo[r[t]][i]-memo[l[t]-1][i];
        }

        int sum = 0;
        for(int i = 0; i < 26; i++){
            sum += usememo[i];
            if(sum >= x[t]){
                cout << (char)(i+'a') << endl;
                break;
            }
        }
    }
    return 0;
}