import copy
import sys
import pypyjit
import itertools
import heapq
import math
from collections import deque, defaultdict
import bisect

input = sys.stdin.readline
sys.setrecursionlimit(10 ** 6)
pypyjit.set_param('max_unroll_recursion=-1')


def index_lt(a, x):
    'return largest index s.t. A[i] < x or -1 if it does not exist'
    return bisect.bisect_left(a, x) - 1


def index_le(a, x):
    'return largest index s.t. A[i] <= x or -1 if it does not exist'
    return bisect.bisect_right(a, x) - 1


def index_gt(a, x):
    'return smallest index s.t. A[i] > x or len(a) if it does not exist'
    return bisect.bisect_right(a, x)


def index_ge(a, x):
    'return smallest index s.t. A[i] >= x or len(a) if it does not exist'
    return bisect.bisect_left(a, x)


N, Q = map(int, input().split())
S = input()[:-1]
C = []
acc = [0] * 26
for c in S:
    acc[ord(c) - ord('a')] += 1
    C.append(copy.deepcopy(acc))


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