N,M = map(int,input().split())
S = input()
NS = len(S)
a,w,c = 0,0,0

for i in range(NS):
    s = S[i]
    if s == "A":
        a += 1
    elif s == "C":
        c += 1
    if a < c:
        print("No")
        exit()

a,w,c = 0,0,0

for i in reversed(range(NS)):
    s = S[i]
    if s == "A":
        a += 1
    elif s == "W":
        w += 1
    if a < w:
        print("No")
        exit()
print("Yes")