import collections

N,M = map(int, input().split())
S = list(input())
A = collections.deque()
W = []
C = []
for i,s in enumerate(S):
    if s=='A':
        A.append(i)
    if s=='W':
        W.append(i)
    if s=='C':
        C.append(i)

for w in W[::-1]:
    if w<A[-1]:
        A.pop()
    else:
        print('No')
        exit()

for c in C:
    if A[0]<c:
        A.popleft()
    else:
        print('No')
        exit()
print('Yes')