S = input().rstrip()
s = list(S)
N = len(s)
t = []
T = []
counter = 0
if N % 2 == 0:
    for i in range(int(N/2)):
        t.append(s[2 * i])
        T.append(s[2 * i + 1])
else:
    for i in range(int((N-1)/2)):
        t.append(s[2 * i])
        T.append(s[2 * i + 1])

if "".join(t).isalpha() is True:
    if "".join(T).isspace() is True:
        print("Yes")
else:
    print("No")