/*
* Author      : Arman Sykot
* Date & time : 28.10.2020 21:47:12 +06
*/

#include <bits/stdc++.h>
#define ll long long
#define the_flash ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)

using namespace std;

int main() {

    the_flash;

    int n;
    cin >> n;

    int arr[n][n];

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++)
            cin >> arr[i][j];
    }

    for (int i = 0; i < n; i++) {
        for (int j = 0; j <= i; j++) {
            cout << arr[i - j][j] << " ";
        }
    }

    for (int i = n; i < 2 * n - 1; i++) {
        for (int j = n - 1; j >= i - (n - 1); j--)
            cout << arr[j][i - j] << " ";
    }

    cout << "\n";

    return 0;
}