#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("YES");}else{puts("NO");}
#define MAX_N 200005

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

    int f[n+1][26];
    rep(i,n+1)rep(j,26) f[i][j] = 0;
    rep(i,n){
        int x = s[i] - 'a';
        rep(j,26) f[i+1][j] = f[i][j];
        f[i+1][x]++;
    }

    rep(_,q){
        int l, r, x;
        cin >> l >> r >> x;
        int g[26] = {};
        rep(j,26){
            g[j] = f[r][j] - f[l-1][j];
        }
        int cnt = 0;
        rep(j,26){
            cnt += g[j];
            if(cnt >= x){
                cout << (char)(j+'a') << endl;
                break;
            }
        }
    }

    return 0;
}