n, q = map(int, input().split())
s = input()
cut = [[0] * 26]
for i in s:
    cut.append(cut[-1][:])
    cut[-1][ord(i) - ord('a')] += 1

for _ in range(q):
    l, r, x = [int(i) for i in input().split()]
    count = [cut[r][i] - cut[l-1][i] for i in range(26)]

    for ind, i in enumerate(count):
        if i >= x:
            print(chr(ind + ord("a")))
            break
        x -= i