Initializing 3D Vectors using Java

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        Vector<Vector<Integer>> v = new Vector<Vector<Integer>>();
        for (int i = 0; i < n; i++) {
            Vector<Integer> temp = new Vector();
            for (int j = 0; j < n; j++) {
                int x = in.nextInt();
                temp.add(x);
            }
            v.add(temp);
        }
        Vector<Vector<Vector<Integer>>> collect = new Vector<Vector<Vector<Integer>>>();
        collect.add(v);
        for (int i = 0; i < (int) collect.size(); i++) {
            for (int j = 0; j < (int) collect.get(i).size(); j++) {
                for (int k = 0; k < (int) collect.get(i).get(j).size(); k++) {
                    System.out.print(collect.get(i).get(j).get(k) + " ");
                }
                System.out.println();
            }
            System.out.println();
        }
    }
}