from itertools import accumulate
N, Q = map(int, input().split())
S = input()
D = [[0] * (N + 1) for _ in range(26)]
for i, s in enumerate(S,start = 1):
    D[ord(s) - 97][i] = 1
for i in range(26):
    D[i] = list(accumulate(D[i]))
for _ in range(Q):
    l, r, x = map(int, input().split())
    cnt = 0
    for i in range(26):
        cnt += D[i][r] - D[i][l - 1]
        if x <= cnt:
            print(chr(97 + i))
            break