#include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>

using namespace std;

int n, m, d, maxans=-2002;

int a[51][51];

int main ()
{
    //freopen("50.txt", "r", stdin);
    freopen("rabbits.in", "r", stdin);
    freopen("rabbits.out", "w", stdout);
    scanf("%d %d %d", &n, &m, &d);
    for(int i=0; i<n; ++i)
    {
        for(int j=0; j<m; ++j)
        {
            scanf("%d", &a[i][j]);
        }
    }
    for(int i1=0; i1<n; ++i1)
    {
        for(int j1=0; j1<m; ++j1)
        {
            for(int i2=0; i2<n; ++i2)
            {
                for(int j2=0; j2<m; ++j2)
                {
                    if((i1==i2 && j1==j2) || abs(i2-i1)+abs(j2-j1)!=d)
                    {
                        continue;
                    }
                    maxans=max(maxans, a[i1][j1]+a[i2][j2]);
                }
            }
        }
    }
    if(maxans<0)
    {
        printf("-1\n");
    }
    else
    {
        printf("%d\n", maxans);
    }
    return 0;
}