#include <iostream>
using namespace std;
int licznik = 0 ;
string liczba [10] ;
string podana ;
string znak ;
int main()
{
while (cin >> znak )
{
if (znak == "+")
{
cin >> podana ;
if (licznik == 10 )
{
cout << "):" << endl ;
}
else
{
licznik ++ ;
liczba [licznik] = podana ; ;
cout << "(:" << endl ;
}
}
else if (znak == "-")
{
if (licznik <= 0 )
{
cout << "):" ;
}
else
{
cout << liczba[licznik] ;
licznik-- ;
}
}
else
{
cout << "):" << endl ;
}
}
return 0;
}
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