#include<bits/stdc++.h>
using namespace std;
int main()
{
    ifstream in("rabbits.in");
    ofstream out("rabbits.out");
    int n,m,d;
    int rate[512][512];
    in>>n>>m>>d;
    for(int i=1; i<=n; i++)
        for(int j=1; j<=m; j++)
            in>>rate[i][j];
    int answer=INT_MIN;
    for(int i=1; i<=n; i++)
    {
        for(int j=1; j<=m; j++)
        {
            for(int k=1; k<=n; k++)
            {
                for(int l=1; l<=m; l++)
                {
                    if(abs(i-k)+abs(j-l)!=d)continue;
                    answer=max(answer, rate[i][j]+rate[k][l]);
                }
            }
        }
    }
    if(answer<0)out<<-1<<endl;
    else out<<answer<<endl;
}
/*
3 3 2
-3 -3 4
-4 -9 0
-10 -4 -3
*/