import java.util.ArrayList;
import java.util.Scanner;
public class StackingBlocks1 {
private static Scanner sc = new Scanner(System.in);
private static ArrayList<String> blocksStacking = new ArrayList<String>();
private static ArrayList<String> blocksRemoved = new ArrayList<String>();
public static void main(String[] args) {
while(sc.hasNext()){
if(manipulation(sc.next())){
//正常に操作が行われているなら、何もしない
}
else{
break;
}
}
for(int i = 0; i < blocksRemoved.size(); i++){
System.out.println(blocksRemoved.get(i));
}
}
public static boolean manipulation(String input){
if(input.compareTo("push") == 0){
String block = sc.next();
blocksStacking.add(block);
return true;
}
else if(input.compareTo("pop") == 0){
int lastIndex = blocksStacking.size() - 1;
String block = blocksStacking.get(lastIndex);
blocksStacking.remove(lastIndex);
blocksRemoved.add(block);
return true;
}
else if(input.compareTo("quit") == 0){
return false;
}
else{
return true;
}
}
}