from sortedcontainers import SortedSet
n, q = map(int, input().split())
s = list(input())
pos = [SortedSet([n]) for _ in range(26)]

def get(c): return ord(c) - ord('a')
for i in range(n): pos[get(s[i])].add(i)

for _ in range(q):
    query = input().split()
    t = query[0]

    if t == "1":
        i = int(query[1]) - 1
        c = query[2]
        pos[get(s[i])].remove(i)
        s[i] = c
        pos[get(s[i])].add(i)

    if t == "2":
        t = query[1]
        p = -1
        for j in range(len(t)):
            if p == n: break
            next_index = pos[get(t[j])].bisect_right(p)
            p = pos[get(t[j])][next_index] 
        if p != n:
            print("Yes")
        else:
            print("No")