#include <bits/stdc++.h>
using namespace std;
#define rep(i, x, limit) for (long long i = (long long)x; i < (long long)limit; i++)
#define REP(i, x, limit) for (long long i = (long long)x; i <= (long long)limit; i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define el '\n'
#define spa " "
#define Yes cout << "Yes" << el
#define No cout << "No" << el
#define YES cout << "YES" << el
#define NO cout << "NO" << el
#define inp(x) for(auto &i:x)cin>>i
#define eps (1e-10)
#define Equals(a,b) (fabs((a) - (b)) < eps )
#define debug(x) cerr << #x << " = " << x << el
using ll = long long;
using ull = unsigned long long;
using i128 = __int128_t;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vvl = vector<vector<ll>>;
using vs = vector<string>;
using vb = vector<bool>;
const double pi = 3.141592653589793238;
const int inf = 1073741823;
const ll infl = 1LL << 60;
const string ABC = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const string abc = "abcdefghijklmnopqrstuvwxyz";
const ll MOD = 998244353;
#include<atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using vm = vector<mint>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  ll n,q;string S;cin>>n>>q>>S;
  vvl C(26,vl(n,0));
  rep(i,0,n){
    C[S[i]-'a'][i]++;
  }
  rep(i,0,26){
    rep(j,0,n-1){
      C[i][j+1]+=C[i][j];
    }
  }
  rep(i,0,q){
    ll l,r,x;cin>>l>>r>>x;
    l--;r--;
    vl stc(26);
    rep(j,0,26){
      stc[j]=C[j][r]-(l>0?C[j][l-1]:0);
    }
    ll cnt=0;
    rep(j,0,26){
      cnt+=stc[j];
      if(cnt>=x){
        cout<<char('a'+j)<<el;
        break;
      }
    }
  }
}