#include <iostream>
#include <fstream>

using namespace std;

ifstream fin("flip.in");
ofstream fout("flip.out");

int n, m, maxi = -1000005;
int a[17][17];
bool opus[17];

int sum(){
    int t = 0;
    for(int i=0;i<n;i++){
        int s = 0;
        for(int j=0;j<m;j++){
            if(opus[j]) s+=a[i][j]*-1;
            else s+=a[i][j];
        }
        if(s<0) t-=s;
        else t+=s;
    }
    return t;
}

int bkt(int j){
    if(j==m){
        return sum();
    }
    opus[j] = true;
    int a = bkt(j+1);
    opus[j] = false;
    int b = bkt(j+1);
    return max(a, b);
}

int main(){
    fin>>n>>m;
    for(int i=0;i<n;i++)
        for(int j=0;j<m;j++)
            fin>>a[i][j];
    fout<<bkt(0);
    return 0;
}