a=list(map(int,input().split()))[::2]
for i in range(3):
    for j in range(i,3):
        if a[i]%2==0 and  a[j]%2==1 or a[i]%2==1 and a[j]%2==0:
            print(":-(")
            break
    else:
        continue
    break
else:
    print(":-)")