#include <iostream>
using namespace std;
int tablica[10];
string znak;
int liczba;
int licznik=-1;
void push (int *tablica, int indeks)
{
cin >> liczba;
if (licznik<9)
{
cout << ":)" << endl;
licznik++;
tablica[licznik]=liczba;
}
else cout << ":(" << endl;
}
void pop (int *tablica, int indeks)
{
if (licznik<0)
cout << ":(" << endl;
else
{
cout << tablica[licznik] << endl;
licznik--;
}
}
int main()
{
while (cin >> znak)
{
if (znak == "+")
push (tablica, 10);
else if (znak == "-")
pop (tablica, 10);
}
return 0;
}
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