import typing
class FenwickTree:
    def __init__(self, n: int = 0) -> None:
        self._n = n
        self.data = [0] * n
    def add(self, p: int, x: typing.Any) -> None:
        assert 0 <= p < self._n
        p += 1
        while p <= self._n:
            self.data[p - 1] += x
            p += p & -p
    def sum(self, left: int, right: int) -> typing.Any:
        assert 0 <= left <= right <= self._n
        return self._sum(right) - self._sum(left)
    def _sum(self, r: int) -> typing.Any:
        s = 0
        while r > 0:
            s += self.data[r - 1]
            r -= r & -r
        return s

N, Q = map(int, input().split())
S = input()
D = [FenwickTree(N) for _ in range(26)]
for i, s in enumerate(S):
    D[ord(s) - 97].add(i, 1)
for _ in range(Q):
    l, r, x = map(int, input().split())
    cnt = 0
    for i in range(26):
        cnt += D[i].sum(l - 1, r)
        if x <= cnt:
            print(chr(97 + i))
            break