import java.util.ArrayList;
import java.util.Scanner;

public class Main {
    
    public void printResult(int[][] operation) {
        ArrayList<Integer> list = new ArrayList<Integer>();
        for(int i = 0;i < operation.length;i++) {
            if(operation[i][0] == 1)
                list.add(operation[i][1]);
            else {
                if(operation[i][0] == 2) {
                    if(list.size() == 0) {
                        System.out.println("no");
                        return; //注意，此时题意要求直接退出
                    }
                    else {
                        System.out.println(list.get(0));
                        list.remove(0);
                    }
                } else if(operation[i][0] == 3) {
                    System.out.println(list.size());
                }
            }
        }
        return;
    }
    
    public static void main(String[] args) {
        Main test = new Main();
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        if(n < 1 || n > 50)
            return;
        int[][] operation = new int[n][2];
        for(int i = 0;i < n;i++) {
            int a = in.nextInt();
            if(a == 1) {
                int b = in.nextInt();
                operation[i][0] = a;
                operation[i][1] = b;
            } else {
                operation[i][0] = a;
            }
        }
        test.printResult(operation);
    }
}