S = input()

if len(S) % 2 == 0:
    print("No")
else:
    ok = True
    for i, s in enumerate(S):
        if i % 2 == 0 and s != " ":
            continue
        if i % 2 == 1 and s == " ":
            continue
        ok = False
    if not ok:
        print("No")
    else:
        print("Yes")