#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");


int main()
{
    int N,M,i,j,s;
    int sfinal=0;
    int a[20][20];
    fin>>N>>M;
    for(i=1;i<=N;++i)
       {
           s=0;
           for(j=1;j<=M;++j)
              {fin>>a[i][j]; s+=a[i][j];}
           if(-1*s>s)
             for(j=1;j<=M;++j)
                a[i][j]*=-1;
       }
    for(j=1;j<=M;++j)
    {
        s=0;
        for(i=1;i<=N;++i)
            s+=a[i][j];
        if(-1*s>s) sfinal+=-1*s;
        else sfinal+=s;
    }
    fout<<sfinal;
    return 0;
}