#include<bits/stdc++.h>
using namespace std;
int n,m,h,a[1010][1010];
int main(){
cin>>n>>m>>h;
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
cin>>a[i][j];
}
}
int cnt=0;
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
int maxn=max({a[i][j],a[i][j+1],a[i+1][j],a[i+1][j+1],a[i-1][j-1],a[i-1][j+1],a[i+1][j-1],a[i-1][j],a[i][j-1]});
int minn=min({a[i][j],a[i][j+1],a[i+1][j],a[i+1][j+1],a[i-1][j-1],a[i-1][j+1],a[i+1][j-1],a[i-1][j],a[i][j-1]});
if(maxn-minn<=h){
cnt=max(cnt,a[i][j]+a[i][j+1]+a[i+1][j]+a[i+1][j+1]+a[i-1][j-1]+a[i-1][j+1]+a[i+1][j-1]+a[i-1][j]+a[i][j-1]) ;
}
}
}
cout<<cnt;
return 0;
}