#include <iostream>
using namespace std;
char znak;
int i=0;
int stos[10];
int main()
{
while (cin>>znak)
{
if (znak == '+')
{
cin>>stos[i];
if (i<=9)
{
cout<<":)"<<endl;
i++;
}
else cout<<":("<<endl;
}
else if (znak == '-')
{
if (i>0)
{
i--;
cout<<stos[i]<<endl;
}
else cout<<":("<<endl;
}
}
return 0;
}
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