#include <iostream>
#include <iomanip>
#include <cstdio>
#include <queue>
#include <cstring>
#include <vector>
#include <map>
#include <algorithm>
#include <cctype>
#include <cmath>
#include <bitset>
#include <set>
#include <deque>
#include <stack>
#include <atcoder/all>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < (t); ++i)
#define dsrep(i,t,s) for(int i = (t)-1; i >= (s); --i)
#define rng(a) a.begin(),a.end()
#define rrng(a) a.rbegin(),a.rend()
#define isin(x,l,r) ((l) <= (x) && (x) < (r))
int dx4[4]={1,0,-1,0};
int dy4[4]={0,-1,0,1};
using ll = long long;
using uint = unsigned;
using ull = unsigned long long;
using P = pair<int,int>;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
const ll mod = 998244353;

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

  int n, q;
  string s;
  cin >> n >> q >> s;

  vector<vector<int>> sum(n + 1, vector(26, 0));
  rep(i, n) {
    rep(j, 26) sum[i + 1][j] = sum[i][j];
    int t = s[i] - 'a';
    sum[i + 1][t] += 1;
  }

  rep(i, q) {
    int l, r, x;
    cin >> l >> r >> x;

    int t = 0;
    rep(j, 26) {
      t += sum[r][j] - sum[l - 1][j];
      if(t >= x) {
        cout << (char)('a' + j) << endl;
        break;
      }
    }
  }
}