import itertools
N,Q = map(int,input().split())
S = input()
L = []
for i in range(26):
    L.append([0]*N)

for i in range(N):
    L[ord(S[i])-97][i] = 1

ACL = []
for i in range(26):
    ACL.append(list(itertools.accumulate(L[i]))+[0])

for _ in range(Q):
    l,r,x=map(int,input().split())
    l-=1
    r-=1
    for i in range(26):
        x-=ACL[i][r]-ACL[i][l-1]
        if x<=0:
            print(chr(i+97))
            break