#include <iostream>
#include <fstream>
#include <limits.h>
#include <algorithm>

using namespace std;

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

int n,m,x[18][18];
int suma,s,maxim=INT_MIN,lim;

int flip(){
    suma=0;
    for(int i=1;i<=n;++i){
        s=0;
        for(int j=1;j<=m;++j)
            s+=-x[0][j]*x[i][j];
        if(s>=0)
            suma+=s;
        else
            suma+=-s;
    }
    return suma;}

int main()
{
    fin>>n>>m;
    for(int i=1;i<=n;++i)
        for(int j=1;j<=m;++j)
            fin>>x[i][j];
    lim=1<<m;
    for(int i=1;i<=lim;++i){
        for(int j=1;j<=m;++j){
            if(i&(1<<(j-1)))
                x[0][j]=-1;
            else
                x[0][j]=1;}
        maxim=max(maxim,flip());
    }
    fout<<maxim;
    return 0;
}