AB = [int(i) for i in input().split()]

s = 0
b = 0
for i, x in enumerate(AB):
    x = 2 - (x % 2)
    if i % 2 == 0:
        b = x
    else:
        s += b ** x

if s % 2 == 0:
    print(':-)')
else:
    print(':-(')