from collections import deque

n, m = map(int, input().split())
S = list(input())

A = deque()
W = deque()
for i in range(2 * (n + m)):
    if S[i] == 'A':
        A.append(i)
    elif S[i] == 'C':
        if len(A) > 0:
            A.popleft()
        else:
            print("No")
            exit()
    else:
        W.append(i)

for i in range(n):
    if A[i] < W[i]:
        print("No")
        exit()
print("Yes")