#include <iostream>
using namespace std;
int main() {
int tab[10],l,i=0;
char z;
cin>>z;
do
{
switch(z)
{
case '+':
{
cin>>l;
if (i>9)
{
cout<<":("<<endl;
i--;
}
else
{
tab[i]=l;
cout<<":)"<<endl;
i++;
}
}
break;
case '-':
{
i--;
if(i<0)
{
cout<<":("<<endl;
i++;
}
else
{
cout<<tab[i]<<endl;
tab[i]=0;
}
}
break;
}
}
while(cin>>z);
return 0;
}
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