#include "bits/stdc++.h"

#define MOD 1000000007
#define rep(i, n) for(ll i=0; i < (n); i++)
#define rrep(i, n) for(ll i=(n)-1; i >=0; i--)
#define ALL(v) v.begin(),v.end()
#define rALL(v) v.rbegin(),v.rend()
#define FOR(i, j, k) for(ll i=j;i<k;i++)
#define debug_print(var) cerr << #var << "=" << var <<endl;
#define DUMP(i, v)for(ll i=0;i<v.size();i++)cerr<<v[i]<<" "
#define fi first
#define se second

using namespace std;
typedef long long int ll;
typedef vector<ll> llvec;
typedef vector<double> dvec;
typedef pair<ll, ll> P;
typedef long double ld;
struct edge{ll x, c;};

/**************************************
** A main function starts from here  **
***************************************/
int main(){
  ll N, Q;
  string S;
  cin >> N >> Q;
  cin >> S;
  vector<llvec> loc(26);
  rep(i, N){
    loc[S[i]-'a'].push_back(i+1);
  }

  while(Q--){
    ll l, r, x;
    cin >> l >> r >> x;
    ll cnt = 0;
    rep(k, 26){
      cnt += upper_bound(ALL(loc[k]), r) - lower_bound(ALL(loc[k]), l);
      if(cnt>=x){
        cout << (char)('a'+k)<<endl;
        break;
      }
    }
  }
  
  return 0;
}