import sys

sys.setrecursionlimit(10**6)
int1 = lambda x: int(x)-1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.buffer.readline())
def FI(): return float(sys.stdin.buffer.readline())
def LI(): return list(map(int, sys.stdin.buffer.readline().split()))
def LI1(): return list(map(int1, sys.stdin.buffer.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def BI(): return sys.stdin.buffer.readline().rstrip()
def SI(): return sys.stdin.buffer.readline().rstrip().decode()
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
dij = [(0, 1), (1, 0), (1, 1), (1, -1)]
inf = 10**19
# md = 998244353
md = 10**9+7

class BitSum:
    def __init__(self, n):
        self.n = n+1
        self.table = [0]*self.n

    def add(self, i, x):
        i += 1
        while i < self.n:
            self.table[i] += x
            i += i & -i

    # [0,i]の和
    def sum(self, i):
        i += 1
        res = 0
        while i > 0:
            res += self.table[i]
            i -= i & -i
        return res

    # [l,r)の和
    def sumlr(self, l, r):
        if l >= r: return 0
        if l == 0: return self.sum(r-1)
        return self.sum(r-1)-self.sum(l-1)

    # 数列を度数分布とみたときに、x番目がどのインデックスにあるかを返す
    # xが大きすぎるときは配列の長さnを返す
    def rank(self, x):
        idx = 0
        for lv in range((self.n-1).bit_length()-1, -1, -1):
            mid = idx+(1 << lv)
            if mid >= self.n: continue
            if self.table[mid] < x:
                x -= self.table[mid]
                idx += 1 << lv
        return idx

n, q = LI()
s = BI()
bit = [BitSum(n) for _ in range(26)]
for i, c in enumerate(s):
    c -= 97
    bit[c].add(i, 1)

for _ in range(q):
    l,r,x=LI()
    now=0
    for c in range(26):
        now+=bit[c].sumlr(l-1,r)
        if now>=x:
            print(chr(c+97))
            break