#include <iostream>
#include <fstream>
using namespace std;
long long n,m,a[17][17],s1,s2,smax,i,j;
int main()
{
    ifstream fin("flip.in");
    ofstream fout("flip.out");
    fin>>n>>m;
    for(i=1;i<=n;i++)
    for(j=1;j<=m;j++)
    fin>>a[i][j];
    smax=0;
    for(i=1;i<=n;i++)
    {
        s1=0;
        s2=0;
        for(j=1;j<=m;j++)
        {
            s1=s1+a[i][j];
            s2=s2+(-1)*a[i][j];
        }
        if(s1>s2)smax=smax+s1;
        else smax=smax+s2;

    }
    fout<<smax;
    fin.close();
    fout.close();
    return 0;
}