#define LL long long
using namespace std;
const int N = 1010;
int M,N,H;
int a[N][N];
int row_max[N][N], row_min[N][N];
int mat_max[N][N], mat_min[N][N];
deque<int> dq;
int main(){
    cin>>M>>N>>H;
    for(int i=1;i<=M;i++){
        for(int j=1;j<=N;j++){
            cin>>a[i][j];
        }
    }
    for(int i=1;i<=M;i++){
        dq.clear();
        for(int j=1;j<=N;j++){
            while(!dq.empty() && j-dq.front()>=3) dq.pop_front();
            while(!dq.empty() && a[i][dq.back()]<=a[i][j]) dq.pop_back();
            dq.push_back(j);
            if(j>=3) row_max[i][j-1] = a[i][dq.front()];
        }
        dq.clear();
        for(int j=1;j<=N;j++){
            while(!dq.empty() && j-dq.front()>=3) dq.pop_front();
            while(!dq.empty() && a[i][dq.back()]>=a[i][j]) dq.pop_back();
            dq.push_back(j);
            if(j>=3) row_min[i][j-1] = a[i][dq.front()];
        }
    }
    for(int j=2;j<=N-1;j++){
        dq.clear();
        for(int i=1;i<=M;i++){
            while(!dq.empty() && i-dq.front()>=3) dq.pop_front();
            while(!dq.empty() && row_max[dq.back()][j]<=row_max[i][j]) dq.pop_back();
            dq.push_back(i);
            if(i>=3) mat_max[i-1][j] = row_max[dq.front()][j];
        }
        dq.clear();
        for(int i=1;i<=M;i++){
            while(!dq.empty() && i-dq.front()>=3) dq.pop_front();
            while(!dq.empty() && row_min[dq.back()][j]>=row_min[i][j]) dq.pop_back();
            dq.push_back(i);
            if(i>=3) mat_min[i-1][j] = row_min[dq.front()][j];
        }
    }
    LL pre[N][N]={0};
    for(int i=1;i<=M;i++){
        for(int j=1;j<=N;j++){
            pre[i][j] = pre[i-1][j] + pre[i][j-1] - pre[i-1][j-1] + a[i][j];
        }
    }
    LL ans=0;
    for(int i=2;i<=M-1;i++){
        for(int j=2;j<=N-1;j++){
            if(mat_max[i][j] - mat_min[i][j] <= H){
                LL sum = pre[i+1][j+1] - pre[i-2][j+1] - pre[i+1][j-2] + pre[i-2][j-2];
                ans = max(ans, sum);
            }
        }
    }
    cout<<ans<<endl;
    return 0;
}
//:)
//114514

找豆包写的