import sys
sys.set_int_max_str_digits(0)
from bisect import bisect_left, bisect_right
from collections import deque, defaultdict, Counter
from itertools import product, combinations, permutations, groupby, accumulate
from heapq import heapify, heappop, heappush

N, Q = map(int, input().split())
S = input()
cnt = [[0] * (N + 1) for _ in range(26)]
for i, s in enumerate(S):
    cnt[ord(s) - 97][i + 1] += 1

for s in range(26):
    for i in range(N):
        cnt[s][i + 1] += cnt[s][i]

ansl = []
for _ in range(Q):
    l, r, x = map(int, input().split())
    memo = 0
    ans = 'a'
    for s in range(26):
        # cnt[s][r] - cnt[s][l - 1]
        memo += cnt[s][r] - cnt[s][l - 1]
        # びったりかオーバーランしたらその文字
        if memo >= x:
            ans = chr(97 + s)
            break
    ansl.append(ans)
print(*ansl, sep='\n')