#include<fstream>
using namespace std;

int a[100][100];

int main()
{
    ifstream f("flip.in");
    ofstream g("flip.out");
    
    int n, m;
    int i,j,s = 0,saux = 0;
    
    f>>n>>m;    
    for(i = 1; i <= n; i ++)
          for (j = 1; j <= m; j ++)
          {
              f>>a[i][j];
              a[i][0] += a[i][j];
              a[0][j] += a[i][j];
              s += a[i][j];    
          }
    for(i = 1; i <= n; i++)
          if (a[i][0] < 0) saux += (-2)*a[i][0];
    for(j = 1; j <= m; j++)
          if (a[0][j] < 0) saux += (-2)*a[0][j];
          
    g<< s + saux;
    
    f.close();
    g.close();
    return 0;
}