#include<iostream>
#include<fstream>
#include<math.h>
#define NMAX 16
using namespace std;

int main(){
    ifstream fin("flip.in");
    ofstream fout("flip.out");
    int n,m,a[NMAX][NMAX], max=-100000;
    fin>>n>>m;

    for(int i = 0; i<n;++i)
        for(int j = 0; j< m; ++j)
            fin>>a[i][j];
    
    for(int i = 0; i<pow(2,n); ++i){
        int sum = 0;
        for(int j = 0; j<m; ++j){
            int s=0;
            for(int k =0; k< n; ++k){
                if(((1<<k) & i)!=0){
                    s += -a[k][j];
                }
                else s += a[k][j];
            
            }
            sum += (s > 0)? s: s*(-1);
        }
        max = (sum > max)? sum: max;
        
    }
    fout<<max;
}