#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

#define sc1(a) scanf("%lld",&a)
#define sc2(a,b) scanf("%lld %lld",&a,&b)

#define pf1(a) printf("%lld\n",a)
#define pf2(a,b) printf("%lld %lld\n",a,b)

#define mx 100005
#define mod 10000007
#define Accepted 0

int main()
{
    int n;

    scanf("%d", &n);
    int a[100][100];

    for (int i = 0; i < n; ++i)
        for (int j = 0; j < n; ++j)
            scanf("%d", &a[i][j]);

    for (int i = 0; i < 2*n-1; ++i)
    {
        for (int j = 0; j <= i && j < n; ++j)
        {
            int k = i - j;
            if (k >= 0 && k < n)
                printf("%d ", a[k][j]);
        }
    }


    return Accepted;
}