#line 1 "/workspaces/compro/lib/template.hpp"


#line 1 "/workspaces/compro/lib/io/vector.hpp"
#include <iostream>
#include <vector>

#ifndef IO_VECTOR
#define IO_VECTOR

template <class T> std::ostream &operator<<(std::ostream &out, const std::vector<T> &v) {
  int size = v.size();
  for (int i = 0; i < size; i++) {
    std::cout << v[i];
    if (i != size - 1)
      std::cout << " ";
  }
  return out;
}

template <class T> std::istream &operator>>(std::istream &in, std::vector<T> &v) {
  for (auto &el : v) {
    std::cin >> el;
  }
  return in;
}

#endif
#line 4 "/workspaces/compro/lib/template.hpp"
#include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; i < n; i++)
#define FOR(i, m, n) for (int i = m; i < n; i++)
#define ALL(v) (v).begin(), (v).end()
#define coutd(n) cout << fixed << setprecision(n)
#define ll long long int
#define vl vector<ll>
#define vi vector<int>
#define MM << " " <<

using namespace std;

template <class T> void chmin(T &a, T b) {
  if (a > b)
    a = b;
}

template <class T> void chmax(T &a, T b) {
  if (a < b)
    a = b;
}

// 重複を消す。計算量はO(NlogN)
template <class T> void unique(std::vector<T> &v) {
  std::sort(v.begin(), v.end());
  v.erase(std::unique(v.begin(), v.end()), v.end());
}


#line 2 "main.cpp"

void solve(long long N, int Q, std::string S, const std::vector<long long> &L, const std::vector<long long> &R,
           const std::vector<long long> &X) {
  vector<vector<int>> cum(N + 1, vi(26, 0));
  FOR(i, 1, N + 1) {
    REP(j, 26) {
      cum[i][j] += cum[i - 1][j];
      if (S[i - 1] - j == 'a') {
        cum[i][j]++;
      }
    }
  }

  REP(i, Q) {
    int tmp = 0;
    REP(j, 26) {
      tmp += cum[R[i]][j] - cum[L[i]][j];
      if (tmp >= X[i]) {
        cout << (char)('a' + j) << endl;
        break;
      }
    }
  }
}

// generated by online-judge-template-generator v4.7.1 (https://github.com/online-judge-tools/template-generator)
int main() {
  int N;
  int Q;
  std::string S;
  std::cin >> N >> Q;
  std::vector<long long> L(Q), R(Q), X(Q);
  std::cin >> S;
  for (int i = 0; i < Q; ++i) {
    std::cin >> L[i] >> R[i] >> X[i];
    L[i]--;
  }
  solve(N, Q, S, L, R, X);
  return 0;
}