import java.util.*;

public class AntiDiagonalMatrices {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter number of rows: ");
        int n = sc.nextInt();
        int[][] arr = new int[n][n];
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                arr[i][j] = sc.nextInt();
            }
        }

        ArrayList<Integer>[] nondiag = new ArrayList[2*n - 1];
        for (int i = 0; i < 2*n-1; i++) {
            nondiag[i] = new ArrayList<Integer>();
        }

        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                nondiag[i+j].add(arr[i][j]);
            }
        }

        System.out.println();
        for (int i = 0; i < 2*n-1; i++) {
            System.out.println(nondiag[i]);
        }

        sc.close();

    }

}