from collections import defaultdict as dd

N, Q = map(int, input().split())
S = input()
A = [ord(S[i]) - ord('a') + 1 for i in range(N)]

B = [[0] * N for i in range (8)]
B[0] = A
for i in range(1, 8):
	for j in range(N - i):
		B[i][j] = B[i - 1][j] << 5 | A[j + i]

cnt = dd(int)
for i in range(8):
	for j in range(N - i):
		cnt[B[i][j]] += 1

for _ in range(Q):
	cmd = list(input().split())
	
	if cmd[0] == '1':
		k = int(cmd[1]) - 1
		A[k] = ord(cmd[2]) - ord('a') + 1
		
		cnt[B[0][k]] -= 1
		B[0][k] = A[k]
		cnt[B[0][k]] += 1
		for i in range(1, 8):
			for j in range(max(0, k - i), min(N - i, k + 1)):
				cnt[B[i][j]] -= 1
				B[i][j] = B[i - 1][j] << 5 | A[j + i]
				cnt[B[i][j]] += 1
	
	if cmd[0] == '2':
		v = 0
		for c in cmd[1]:
			v = v << 5 | (ord(c) - ord('a') + 1)
		
		print("Yes" if cnt[v] else "No")