#include <cstdio>

using namespace std;
FILE *f=fopen("flip.in","r");
FILE *g=fopen("flip.out","w");
int main()
{
    int n,m,i,j,col,rand,s=0;
    fscanf(f,"%d %d",&n,&m);
    int v[n][m];
    for (i=0;i<n;i++)
        for (j=0;j<m;j++)
        {
        fscanf(f,"%d",&v[i][j]);
        if (v[i][j]==0)
        {
            col=j;
            rand=i;
        }
        }
    for (i=0;i<n;i++)
        v[i][col]*=-1;
    for (i=0;i<m;i++)
        v[rand][i]*=-1;
    for (i=0;i<n;i++)
        for (j=0;j<m;j++)
        s+=v[i][j];
    fprintf(g,"%d",s);
    return 0;
}