/*
ID: espr1t
TASK: 
KEYWORDS: 
*/

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#include <string>

using namespace std;
FILE *in; FILE *out;

const int MAX = 52;
const int INF = 1000000001;

int n, m, k;
int a[MAX][MAX];

int main(void) {
	in = stdin; out = stdout;
	in = fopen("rabbits.in", "rt"); out = fopen("rabbits.out", "wt");
	
	fscanf(in, "%d %d %d", &n, &m, &k);
	for (int row = 0; row < n; row++)
	   for (int col = 0; col < m; col++)
	       fscanf(in, "%d", &a[row][col]);
	
	int ans = -INF;
	for (int srow = 0; srow < n; srow++) {
	    for (int scol = 0; scol < m; scol++) {
	        for (int erow = 0; erow < n; erow++) {
	            for (int ecol = 0; ecol < m; ecol++) {
	                if (abs(srow - erow) + abs(scol - ecol) == k) {
	                    ans = max(ans, a[srow][scol] + a[erow][ecol]);
                    }
                }
            }
        }
    }
    fprintf(out, "%d\n", ans < 0 ? -1 : ans);
	
	return 0;
}