s = list(map(int, input().split()))

ans = []

for i in range(0, len(s), 2):
    a = s[i]
    b = s[i+1]
    if (a * b) % 2 == 0:
        ans.append(True)
    else:
        ans.append(False)

c = ans.count(True)
if c == 3:
    print(':-)')
else:
    print(':-(')