#include <iostream>
using namespace std;

int v[30][30];
int Elem[626];
int indice;

int main()
{

    int N;
    cin >> N;
    for (int i=1;i<=N;i++)
      for (int j=1;j<=N;j++)
        cin >> v[i][j];

    int sens=-1;
    for (int i=1;i<=N;i++)
    {

      for (int j=1;j<=i;j++)
        if (sens == -1) Elem[++indice]=v[j][i-j+1];
        else  Elem[++indice]=v[i-j+1][j];

      sens=sens*-1;
    }

    for (int i=2;i<=N;i++)
    {
      for (int j=i;j<=N;j++)
        if (sens == -1) Elem[++indice]=v[j][N-j+i];
        else  Elem[++indice]=v[N-j+i][j];

      sens=sens*-1;
    }

    for (int i=1;i<=indice;i++) cout <<Elem[i] << " ";
    return 0;
}