//Normal

#define _GLIBCXX_DEBUG
#define ll long long
#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

void print(auto a){
  cout << a;
}

void prints(auto a){
  cout << a << " ";
}

void prints(){
  cout << " ";
}

void printl(auto a){
  cout << a << endl;
}

void printl(){
  cout << endl;
}

void fix(int n){
  cout << fixed << setprecision(n);
}

int main(){
  bool flag = true;
  int A, B;
  
  while(cin >> A >> B){
    if(A%2 != 0) flag = !flag;
  }
  
  flag ? printl(":-)") : printl(":-(");
  
  return 0;
}