n, q = map(int, input().split())
S = input()
d = 26
C = [[0]*(n+1) for _ in range(d)]
for i, s in enumerate(S):
    for j in range(d):
        C[j][i+1] += C[j][i]
    c = ord(s) - ord('a')
    C[c][i+1] += 1
for _ in range(q):
    l, r, x = map(int, input().split())
    l -= 1
    for j in range(d):
        x -= C[j][r] - C[j][l]
        if x <= 0:
            break
    print(chr(j + ord('a')))