#include <cstdio>
const int MAXN = 50, MAXM = 50;
int a[MAXN][MAXM];
int main()
{
	freopen("rabbits.in", "r", stdin);
	freopen("rabbits.out", "w", stdout);
	int n, m, d, i, j, k, temp, best = -1;
	scanf("%d%d%d", &n, &m, &d);
	for(i = 0; i < n; i++)
		for(j = 0; j < m; j++)
			scanf("%d", &a[i][j]);
	for(i = 0; i < n; i++)
		for(j = 0; j < m; j++)
			for(k = 0; k <= d; k++)
			{
				if(i + k < n && j + d - k < m)
				{
					temp = a[i][j] + a[i + k][j + d - k];
					if(best < temp)
						best = temp;
				}
				if(i >= k && j + d - k < m)
				{
					temp = a[i][j] + a[i - k][j + d - k];
					if(best < temp)
						best = temp;
				}
			}	
	printf("%d\n", best);
	return 0;
}