n, q = map(int, input().split())
S = input()
DP = [[0 for _ in range(26)] for _ in range(n + 1)]
for i in range(n):
    idx = ord(S[i]) - ord('a')
    for j in range(26):
        if j == idx:
            DP[i + 1][j] = DP[i][j] + 1
        else:
            DP[i + 1][j] = DP[i][j]

for _ in range(q):
    l, r, x = map(int, input().split())
    l -= 1
    cnt = 0
    for i in range(26):
        temp = DP[r][i] - DP[l][i]
        if cnt + temp >= x:
            print(chr(ord('a') + i))
            break
        cnt += temp