n, m = map(int, input().split())
s = input()
w = []
a = []
c = []
for i in range((n + m) * 2):
    if s[i] == 'W':
        w.append(i)
    elif s[i] == 'A':
        a.append(i)
    else:
        c.append(i)
for i in range(n):
    if w[i] > a[i + n]:
        print('No')
        exit(0)
for i in range(m):
    if a[i] > c[i]:
        print('No')
        exit(0)
print('Yes')