S = input()
S1 = [S[i] for i in range(len(S)) if i % 2 == 0]
S2 = [S[i] for i in range(len(S)) if i % 2 == 1]
bl = True
for s in S1:
    if s == ' ':
        bl = False
for s in S2:
    if s != ' ':
        bl = False
print('Yes') if bl else print('No')