import sys
#sys.setrecursionlimit(10 ** 6)
INF = float('inf')
#10**20に変えるのもあり
MOD = 10**9 + 7
MOD2 = 998244353
def solve():
    def II(): return int(sys.stdin.readline())
    def LI(): return list(map(int, sys.stdin.readline().split()))
    def LC(): return list(input())
    def IC(): return [int(c) for c in input()]
    def MI(): return map(int, sys.stdin.readline().split())
    Alpha = {}
    for i in range(97, 123):
        Alpha[chr(i)] = i - 97
        Alpha[i-97] = chr(i)
    N,Q = MI()
    S = LC()
    Scum = [[0]*26 for _ in range(N+1)]
    for n,s in enumerate(S):
        for i in range(26):
            Scum[n+1][i] += Scum[n][i]
        Scum[n+1][Alpha[s]] += 1
    from pprint import pprint
    #pprint(Scum)
    from copy import deepcopy
    for q in range(Q):
        L,R,X = MI()
        L-=1

        TmpR = deepcopy(Scum[R])
        TmpL = deepcopy(Scum[L])
        #print(TmpL)
        for i in range(26):
            TmpR[i] =TmpR[i] -TmpL[i]
        CharNum = 0
        #print(TmpR)
        for i in range(26):
            CharNum += TmpR[i]
            if(CharNum >= X):
                #print(i)
                print(Alpha[i])
                break
    return
solve()