#include <bits/stdc++.h>

using i32 = std::int32_t;
using u32 = std::uint32_t;
using i64 = std::int64_t;
using u64 = std::uint64_t;
using i128 = __int128_t;
using u128 = __uint128_t;
using isize = std::ptrdiff_t;
using usize = std::size_t;

class rep {
    struct Iter {
        usize itr;
        constexpr Iter(const usize pos) noexcept : itr(pos) {}
        constexpr void operator++() noexcept { ++itr; }
        constexpr bool operator!=(const Iter& other) const noexcept {
            return itr != other.itr;
        }
        constexpr usize operator*() const noexcept { return itr; }
    };
    const Iter first, last;

  public:
    explicit constexpr rep(const usize first, const usize last) noexcept
        : first(first), last(std::max(first, last)) {}
    constexpr Iter begin() const noexcept { return first; }
    constexpr Iter end() const noexcept { return last; }
};

template <class T> using Vec = std::vector<T>;

void C_main() {
    usize N, Q;
    std::cin >> N >> Q;
    std::string S;
    std::cin >> S;
    Vec<std::array<usize, 26>> sum(N + 1);
    for (const auto i : rep(0, N)) {
        for (const auto j : rep(0, 26)) {
            sum[i + 1][j] += sum[i][j];
        }
        sum[i + 1][S[i] - 'a'] += 1;
    }
    while (Q--) {
        usize l, r, x;
        std::cin >> l >> r >> x;
        l -= 1;
        std::array<usize, 26> cnt;
        for (const auto j : rep(0, 26)) {
            cnt[j] = sum[r][j] - sum[l][j];
        }
        for (const auto j : rep(0, 26)) {
            if (cnt[j] >= x) {
                std::cout << (char)('a' + j) << '\n';
                break;
            } else {
                x -= cnt[j];
            }
        }
    }
}

int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr);
    C_main();
    return 0;
}