#include <bits/stdc++.h>
using namespace std;
int a [50][50], n, m, d;
int main (){

	ifstream fin ("rabbits.in");
	ofstream fout ("rabbits.out");
	fin >> n >> m >> d;
	for (int i = 0; i < n; i ++){
        for (int j = 0; j < m; j ++){
            fin >> a [i][j];
        }
	}
	int maxi = -20000;
	for (int i = 0; i < n; i ++){
        for (int j = 0; j < m; j ++){
            for (int x = 0; x < n; x ++){
                for (int y = 0; y < m; y ++){
                    if (abs (i - x) + abs (j - y) == d) maxi = max (maxi, a [i][j] + a [x][y]);
                }
            }
        }
	}
	fout << max (maxi, -1) << endl;

return 0;
}