#include <iostream>
using namespace std;
int tablica[10];
string znak;
int liczba;
int ile;
int licznik=-1;
int main()
{
cin >> ile;
for (int i = 1; i <= ile; i++)
{
cin >> znak;
if (znak == "+")
{
cin >> liczba;
if (licznik<9)
{
cout << ":)" << endl;
licznik++;
tablica[licznik]=liczba;
}
else cout << ":(" << endl;
}
else if (znak == "-")
{
if (licznik<0)
cout << ":(" << endl;
else
{
cout << tablica[licznik] << endl;
licznik--;
}
}
}
return 0;
}
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