#include <iostream>
#include <fstream>
using namespace std;
fstream fin("flip.in",ios::in);
fstream fout("flip.out",ios::out);
long n,m,a[16][16],smax;
int main(){
    long i,j,k,s,t;
    fin>>n>>m;
    for(i=0;i<n;i++){
        for(j=0;j<m;j++){fin>>a[i][j];}}
    for(i=0;i<(1<<m);i++){
        s=0;
        for(k=0;k<n;k++){
            for(t=j=0;j<m;j++)
            if(i&(1<<j))t+=-a[k][j];else t+=a[k][j];
            s+=t<-t ? -t:t;
        }
        if(smax<s)smax=s;}fout<<smax;}