#include <iostream>
#include <bits/stdc++.h>
#include <vector>
#include <fstream>
using namespace std;
ifstream f("flip.in");
ofstream g("flip.out");

int main()
{int N, M, sum=0, maxsum=0, i, j, sum1=0, sum2=0;
    f>>N>>M;
    vector <vector <int>> tabel(N, vector <int>(M));
    for(i=0; i<N; i++)
    {
        for(j=0; j<M; j++)
        {
            f>>tabel[i][j];
            sum1=sum1+tabel[i][j];
            maxsum=maxsum+tabel[i][j];
        }
    }
    /*for(i=0; i<N; i++)
    {
        for(j=0; j<M; j++)
        {
            cout<<tabel[i][j]<<" ";

        }
        cout<<endl;
    }
    */
    sum=maxsum;
    for(i=0; i<N; i++)
    {   sum=maxsum;
        for(j=0; j<M; j++)
        {
            sum=sum+(2*(tabel[i][j])*(-1));
        }
        if(sum>maxsum)
        {
            for(int u=0; u<M; u++)
            {
                tabel[i][u]=tabel[i][u]*(-1);
            }
            maxsum=sum;
            //cout<<"Se da flip la coloana "<<i+1<<endl;
        }
    }
    sum=maxsum;
    for(j=0; j<M; j++)
    {   sum=maxsum;
        for(i=0; i<N; i++)
        {
            sum=sum+(2*(tabel[i][j])*(-1));
        }
        if(sum>maxsum)
        {
            for(int u=0; u<N; u++)
            {
                tabel[u][j]=tabel[u][j]*(-1);
            }
            maxsum=sum;
            //cout<<"Se da flip la coloana "<<j+1<<endl;
        }
    }
    /*cout<<endl;
    cout<<endl;
    for(i=0; i<N; i++)
    {
        for(j=0; j<M; j++)
        {
            sum2=sum2+tabel[i][j];
            cout<<tabel[i][j]<<" ";
        }
        cout<<endl;
    }
    cout<<"Sum1="<<sum1<<endl;
    cout<<"Sum2="<<sum2<<endl;
    */
    g<<maxsum;
    return 0;
}