#include <cstdio>
#include <cstring>
using namespace std;

int n,m,mat[20][20],flip[20][20],sumamax=-999999999,v[20];

void verifica()
{
    int i,suma=0,j,sum[20];
    memset(sum,0,sizeof(sum));
    for(i=1;i<=n;++i)
    {
        for(j=1;j<=m;++j)
        {
            if(v[i]==1)
                flip[i][j]=-mat[i][j];
            else
                flip[i][j]=mat[i][j];
        }
    }
    for(i=1;i<=m;++i)
    {
        for(j=1;j<=n;++j)
            sum[i]+=flip[j][i];
        if(sum[i]<0)
            sum[i]=-sum[i];
        suma+=sum[i];
    }
    if(suma>sumamax) sumamax=suma;
}

void back(int k)
{
    int i;
    if(k==n)
        verifica();
    else
    {
        for(i=0;i<=1;++i)
        {
            v[k+1]=i;
            back(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",&mat[i][j]);
            //s+=mat[i][j];
        }
    back(0);
    printf("%d",sumamax);
    return 0;
}