n, m = map(int, input().split())
s = input()
l = len(s)
used = [0] * l
q = []
i = 0
for j in range(l):
    if s[j] == 'C':
        while i < j and s[i] != 'A':
            i += 1
        if i == j:
            print('No')
            exit()
        used[i] = 1
        i += 1
j = l - 1
for i in range(l)[::-1]:
    if s[i] == 'W':
        while j > i and (s[j] != 'A' or used[j]):
            j -= 1
        if j == i:
            print('No')
            exit()
        j -= 1
print('Yes')