#include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; (i) < (int)(n); ++(i))
#define REP3(i, m, n) for (int i = (m); (i) < (int)(n); ++(i))
#define REP_R(i, n) for (int i = (int)(n)-1; (i) >= 0; --(i))
#define REP3R(i, m, n) for (int i = (int)(n)-1; (i) >= (int)(m); --(i))
#define ALL(x) ::std::begin(x), ::std::end(x)
using namespace std;

vector<char> solve(int n, int q, const string& s, const vector<int>& l, const vector<int>& r, const vector<int>& x) {
    vector<array<int, 26> > cnt(n + 1);
    cnt[0] = {};
    REP (i, n) {
        cnt[i + 1] = cnt[i];
        cnt[i + 1][s[i] - 'a'] += 1;
    }
    vector<char> ans(q, '?');
    REP (j, q) {
        int k = x[j] - 1;
        REP (c, 26) {
            k -= cnt[r[j]][c] - cnt[l[j]][c];
            if (k < 0) {
                ans[j] = c + 'a';
                break;
            }
        }
    }
    return ans;
}

// generated by oj-template v4.7.2 (https://github.com/online-judge-tools/template-generator)
int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    constexpr char endl = '\n';
    int N;
    int Q;
    string S;
    cin >> N >> Q;
    vector<int> L(Q), R(Q), X(Q);
    cin >> S;
    REP (i, Q) {
        cin >> L[i] >> R[i] >> X[i];
        -- L[i];
    }
    auto ans = solve(N, Q, S, L, R, X);
    REP (i, Q) { cout << ans[i] << endl; }
    return 0;
}