#include<bits/stdc++.h>
using namespace std;
int  n,m,h;
int a[1003][1003];
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 ans=0;
	for(int i=1;i<=n-2;i++){
		for(int j=1;j<=m-2;j++){
			int  res1=0,res2=100005,sum=0;
			for(int i1=i;i1<=i+2;i1++){
				for(int j1=j;j1<=j+2;j1++){
					res1=max(res1,a[i1][j1]);
					res2=min(res2,a[i1][j1]);
					sum+=a[i1][j1];
				}
			}
			if(res1-res2<=h){
				ans=max(ans,sum);
			}
		}
	}
	cout<<ans;
	return 0;
}

😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😶😑😑😑😑😑😑😑vvvvvvvv

#include<bits/stdc++.h>
using namespace std;
const int N=1010;
typedef long long LL;
int a[N][N];
int main()
{
	int n,m,h;
	cin>>n>>m>>h;
	for(int i=1;i<=n;i++)
	{
		for(int j=1;j<=m;j++)
		{
			cin>>a[i][j];
		}
	}
	int res=0;
	for(int i=1;i+2<=n;i++)
	{
		for(int j=1;j+2<=m;j++)
		{
			int minv=a[i][j],maxv=a[i][j];
			int sum=0;
			for(int x=i;x<=i+2;x++)
			{
				for(int y=j;y<=j+2;y++)
				{
					sum+=a[x][y];
					minv=min(minv,a[x][y]);
					maxv=max(maxv,a[x][y]);
				}
			}
			if(maxv-minv<=h)
			{
				res=max(res,sum);
			}
		}
	}
	cout<<res;
	return 0;
}