n, m = map(int, input().split()) S = input() ans = 0 for s in S: if s == "A": ans += 1 elif s == "C": ans -= 1 if ans < 0: flag = False break ans = 0 flag = True for s in S[::-1]: if s == "A": ans += 1 elif s == "W": ans -= 1 if ans < 0: flag = False break print("Yes" if flag else "No")