#include <fstream>
#include <iostream>

using namespace std;

int n, m;
int array[20][20];

void fill(int a, int y){
     
     
     if (a > 0 && array[a][y] > array[a - 1][y]) {
           array[a - 1][y] = array[a][y];
           fill(a - 1, y);
     }
     if (y > 0 && array[a][y] > array[a][y - 1]) {
           array[a][y - 1] = array[a][y];
           fill(a, y - 1);
     }
     
     if (a < n && array[a][y] >= array[a + 1][y]) {
           array[a + 1][y] = array[a][y];
           fill(a + 1, y);
     }
     
     if (y < m && array[a][y] >= array[a][y + 1]) {
           array[a][y + 1] = array[a][y];
           fill(a, y + 1);
     }
}

int main(int argc, char *argv[])
{
    ifstream data("DATA5.txt");
    ofstream out("OUT5.txt");
    
    for (int index0 = 0; index0 < 5; index0++) {
    int array2[20][20];
    data >> n >> m;
    
         for (int index = 0; index < n; index++) {
        for (int index2 = 0; index2 < m; index2++) {
                data >> array[index][index2];
                array2[index][index2] = array[index][index2];
            }
        }
        fill(0,0);
        
        int sum = 0;
        for (int index = 1; index < n - 1; index++) {
            for (int index2 = 1; index2 < m - 1; index2++) {
                sum += array[index][index2] - array2[index][index2];
            }
        }
        out << sum << endl;
    }
    
    //system("PAUSE");
    return 0;
}