#include <atcoder/segtree>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
const long long INF_LL = 2000000000000000000LL;
const int INF = 2000000000;
const long long MOD = 1000000007;
#define ll long long
#define all(x) x.begin(), x.end()
#define REP(i, a, b) for(int i = a; i < b; i++)
#define rep(i, n) REP(i, 0, n)
// typedef float double;
// typedef priority_queue prique;
typedef pair<ll, ll> P;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<P> vp;
typedef vector<ll> vl;
typedef vector<vi> matrix;
int dx[4] = {0, -1, 0, 1};
int dy[4] = {1, 0, -1, 0};
int sign[2] = {1, -1};
template <class T> bool chmax(T &a, T b) {
    if(a < b) {
        a = b;
        return 1;
    }
    return 0;
}
template <class T> bool chmin(T &a, T b) {
    if(a > b) {
        a = b;
        return 1;
    }
    return 0;
}

ll modpow(ll a, ll b, ll m) {
    if(b == 0)
        return 1;
    ll t = modpow(a, b / 2, m);
    if(b & 1) {
        return (t * t % m) * a % m;
    } else {
        return t * t % m;
    }
}

struct edge {
    int to;
    ll cost;
    edge(int t, ll c) { to = t, cost = c; }
};

typedef vector<vector<edge>> graph;

// using mint = modint998244353;

int op(int a, int b){return a + b;}
int e(){return 0;}

int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(false);
    int n, q;
    cin >> n >> q;
    string s;
    cin >> s;
    vector<segtree<int, op, e>> seg(26, segtree<int, op, e>(n));
    rep(i, n){
        seg[s[i] - 'a'].set(i, 1);
    }
    rep(i, q){
        int l, r, x;
        cin >> l >> r >> x;
        int tmp = 0;
        rep(j, 26){
            tmp += seg[j].prod(l - 1, r);
            if(tmp >= x){
                cout << (char)(j + 'a') << endl;
                break;
            }
        }
    }
}