from collections import deque

N, M = map(int, input().split())
S = input()

s = list(S)
wa = ac = 0
a = deque()
for i in range(len(s)):
    c = S[i]
    if c == 'A':
        a.append(i)
    elif c == 'C':
        if a:
            p = a.popleft()
            ac += 1
            s[p] = '_'

w = 0
for i in range(len(s)):
    c = S[i]
    if c == 'W':
        w += 1
    elif c == 'A':
        if w > 0:
            wa += 1
            w -= 1

if wa >= N and ac >= M:
    print('Yes')
else:
    print('No')