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

import sys
a = 0
for s in S:
    if s == "A":
        a += 1
    elif s == "C":
        if a == 0:
            print('No')
            exit()
        else:
            a -= 1
w = 0
for s in reversed(S):
    if s == "A":a += 1
    elif s == "W":
        if a == 0:
            print('No')
            exit()
        else:a -= 1
print('Yes')