#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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