#include<iostream>
#include<stdio.h>
using namespace std;
int n,m,i,j,S,S2;
int v[200][200];
int main()
{
    FILE*f;f=fopen("flip.in","rb");
    fscanf(f,"%d%d",&n,&m);
    for(i=0;i<n;i++)
        for(j=0;j<m;j++)
            fscanf(f,"%d",&v[i][j]);
    fclose(f);
    for(i=0;i<n;i++)
    {
        S=0;
        S2=0;
        for(j=0;j<m;j++)
            S=S+v[i][j];
        for(j=0;j<m;j++)
            S2=S2+(v[i][j]*-1);
        if(S2>S)
            for(j=0;j<m;j++)
                v[i][j]=v[i][j]*-1;
    }
    for(j=0;j<m;j++)
    {
        S=0;
        S2=0;
        for(i=0;i<n;i++)
            S=S+v[i][j];
        for(i=0;i<n;i++)
            S2=S2+(v[i][j]*-1);
        if(S2>S)
            for(i=0;i<n;i++)
                v[i][j]=v[i][j]*-1;
    }
    S=0;
    for(i=0;i<n;i++)
        for(j=0;j<m;j++)
            S=S+v[i][j];
    FILE*g;g=fopen("flip.out","wb");
    fprintf(g,"%d",S);
    fclose(g);


}