n, q = map(int, input().split())
s = input()
alpha = [[0 for j in range(26)] for i in range(n+1)]

for i in range(1, n+1):
    a = ord(s[i-1]) - ord("a")
    alpha[i][a] += 1
    for j in range(26):
        alpha[i][j] += alpha[i-1][j]

data = [0 for _ in range(26)]

for i in range(q):
    l, r, x = map(int, input().split())
    for j in range(26):
        data[j] = alpha[r][j] - alpha[l-1][j]

    i, v = 0, 0
    while v < x:
        v += data[i]
        i += 1
    print(chr(i-1 + ord("a")))