from collections import deque
n,m = map(int,input().split())
S = input()
le = len(S)
used = [0]*(le)
A = deque()
for i in range(le)[::-1]:
    # print(i,S[i],A)
    if S[i] == "W":
        if not A:
            print("No")
            exit()
        used[A.popleft()] = 1
    
    if S[i] == "A":
        A.append(i)

A = []
for i in range(le):
    # print(i,S[i],A)
    if S[i] == "C":
        if not A:
            print("No")
            exit()
        A.pop()
    if S[i] == "A" and used[i] == 0:
        A.append(i)
print("Yes")