#include<stdio.h>
int main(void)
{
	int m, n;
	int a[400][400] = {}, st[100][100] = {};
	scanf("%d %d", &m, &n);
	int i, j;
	for (i = 1; i <= m; i++)
	{
		for (j = 1; j <= n; j++)
		{
			scanf("%d", &a[i][j]);
		}
	}
	int sum = n * m-1;
	i = j = 1;
	printf("%d ", a[1][1]);
	st[1][1] = 1;
	while (sum > 0)
	{
		if (i < m && j <= n && st[i + 1][j] == 0&&(st[i][j-1]!=0||(st[i][j - 1]==1&&st[i+1][j]==0)||j==1))
		{
			st[i + 1][j] = 1;
			printf("%d", a[i + 1][j]);
			i++;
		}
		else if ((i == m||st[i+1][j]==1) && j < n && st[i][j + 1] == 0)
		{
			st[i][j + 1] = 1;
			printf("%d", a[i][j + 1]);
			j++;
		}
		else if ((j == n||st[i][j+1]==1) && st[i - 1][j] == 0 && i - 1 > 0)
		{
			st[i - 1][j] = 1;
			printf("%d", a[i-1][j]);
			i--;
		}
		else if ((i == 1||st[i-1][j]==1) && st[i][j - 1] == 0 && j - 1 > 0)
		{
			st[i][j - 1] = 1;
			printf("%d", a[i][j - 1]);
			j--;
		}
		sum--;
		if (sum != 0)
			printf(" ");
	}

	return 0;
}