//
//  main.cpp
//  a
//
//  Created by Alex Rancea on 09/11/14.
//  Copyright (c) 2014 Alex Rancea. All rights reserved.
//

#include <iostream>
#include <fstream>

using namespace std;

ifstream f("flip.in");
ofstream g("flip.out");
int main() {
    int n,m,i,a[17][17],j,s1 = 0,s2 = 0;
    f>>n>>m;
    for(i=1;i<=n;i++){
        for(j=1;j<=m;j++){
            f>>a[i][j];
        }
    }
    for(i=1,s1=0,s2=0;i<=n;i++,s1=0,s2=0){
        for(j=1;j<=m;j++){
            s1 = s1 + (-(a[i][j]));
            s2 = s2 + a[i][j];
        }
    if(s1>s2){
        for(j=1;j<=m;j++){
            a[i][j] = -a[i][j];
        }
    }
    }
    for(j=1,s1=0,s2=0;j<=m;j++,s1=0,s2=0){
        for(i=1;i<=n;i++){
            s1 = s1 + (-(a[i][j]));
            s2 = s2 + a[i][j];
        }
        if(s1>s2){
            for(i=1;i<=n;i++){
                a[i][j] = -a[i][j];
            }
        }
    }
    s1=0;
    for(i=1;i<=n;i++){
        for(j=1;j<=m;j++){
            s1 += a[i][j];
        }
    }
    g<<s1;
    return 0;
}