N,Q = map(int,input().split())
S = input()
dat = [[0] * 26 for _ in range(N + 1)]

for i in range(1,N + 1):
    a = ord(S[i-1]) - ord('a')
    dat[i][a] += 1
    for j in range(26):
        dat[i][j] += dat[i-1][j]
u = [0] * 26
for _ in range(Q):
    l,r,x = map(int,input().split())
    for i in range(26):
        u[i] = dat[r][i] - dat[l-1][i]
    i = 0
    s = 0
    while s < x:
        s += u[i]
        i += 1
    print(chr(i-1 + ord('a')))