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


using namespace std;

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

int b[20],m,n,a[20][20],smax=INT_MIN;

void read()
{
    fin>>n>>m;

    for(int i=1;i<=n;++i)
        for(int j=1;j<=m;++j)
        fin>>a[i][j];
}


void sum()
{
    int s=0,sabs=0;

    for(int i=1;i<=n;++i)
    {s=0;
    for(int j=1;j<=m;++j)
        if(b[j])s+=a[i][j];
        else s-=a[i][j];

        if(s<0)sabs-=s;
        else sabs+=s;

    }

    smax=max(sabs,smax);
}

void Generare()
{int i;
while(b[0]==0)
    {  sum();
        for(i=m;b[i]==1;--i)
            b[i]=0;
        b[i]=1;
    }
}

int main()
{   read();
    Generare();
    fout<<smax;
    return 0;
}