#include <iostream>
#include <cstdio>
using namespace std;
#define NMax 17
int colsum[NMax];
const int valmax = 1<<16;
int a[NMax][NMax];
int temp[NMax][NMax];
int b[valmax+1];
int n,m,sumamax,sumcurrent;

void check()
{
    sumcurrent=0;
    int i,j,sumacol=0;
    for(i=1;i<=n;i++)
    {
        for(j=1;j<=m;j++)
        {
            if(b[i]==1)
                temp[i][j]= -1 * a[i][j];
            else
                temp[i][j]= a[i][j];
        }
    }
    for(j=1;j<=m;j++)
    {
        sumacol=0;
        for(i=1;i<=n;i++)
        {
         sumacol=sumacol+temp[i][j];
        }
        if(sumacol>0)
            sumcurrent+=sumacol;
        else
            sumcurrent+= -1 * sumacol;
    }
}
void bk(int k)
{
    if(k==n+1)
    {
        check();
        if(sumamax < sumcurrent)
            sumamax=sumcurrent;
    }
    else
    {
        b[k]=1; bk(k+1);
        b[k]=0; bk(k+1);
    }
}
int main()
{
    int i,j;

    freopen("flip.in","r",stdin);
    freopen("flip.out","w",stdout);

    scanf("%d %d",&n,&m);
    for(i=1;i<=n;i++)
    {
        for(j=1;j<=m;j++)
        {
            scanf("%d",&a[i][j]);
            colsum[j]+=a[i][j];
        }
    }
    bk(1);
    cout<<sumamax;

}