#include <iostream>
#include <fstream>
using namespace std;
ifstream f ("flip.in");
ofstream g ("flip.out");
int a[17][17],n,m,i,j,v[17],s,sum,Max;
int main()
{
    f>>n>>m;
    Max=-1;
    for (i=1;i<=n;i++)
        for (j=1;j<=m;j++)
            f>>a[i][j];
    while (v[m]==0){
        for (i=1;i<=m;i++)
        {
            if (v[i]==1)
                v[i]=0;
            else {
                v[i]=1;
                break;}
        }
        sum=0;
        for (i=1;i<=n;i++){
            s=0;
            for (j=1;j<=m;j++)
            {
                if (v[j]==1)
                    s=s-a[i][j];
                else
                    s=s+a[i][j];
            }
        if (s<0)
            sum=sum-s;
        else
            sum=sum+s;}
        if (sum>Max)
            Max=sum;
    }
    g<<Max;

    return 0;
}