n, m = map(int, input().split())
S = input()

ans = 0
for s in S:
    if s == "A":
        ans += 1
    elif s == "C":
        ans -= 1
        if ans < 0:
            print("No")
            exit()

ans = 0
for s in S[::-1]:
    if s == "A":
        ans += 1
    elif s == "W":
        ans -= 1
        if ans < 0:
            print("No")
            exit()
print("Yes")