#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <cassert>

#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

using namespace std;
typedef long long ll;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    int n, q; cin >> n >> q;
    string s; cin >> s;
    vector<vector<int>> cumsum(n+1, vector<int>(26));
    for(int i = 0; i < n; i++){
        for(int j = 0; j < 26; j++) cumsum[i+1][j] = cumsum[i][j];
        cumsum[i+1][s[i]-'a']++;
    }
    auto count = [&](int idx, int l, int r){
        return cumsum[r][idx]-cumsum[l][idx];
    };
    while(q--){
        int l, r, x; cin >> l >> r >> x; l--; r--;
        int sum = 0;
        for(int i = 0; i < 26; i++){
            sum += count(i, l, r+1);
            if(sum >= x){
                cout << (char)('a'+i) << endl;
                break;
            }
        }
    }
}