#include "bits/stdc++.h"
using namespace std;long long k[10], sum; string ans = ":-)"; int main() { for (int i = 0; i < 6; ++i) { cin >> k[i]; if (i % 2 == 0) { sum += k[i]; } }if (sum % 2) { ans = ":-("; }cout << ans << endl;}