#include<cstdio>
#include<algorithm>
#define nmax 18
using namespace std;
int n,m,a[nmax][nmax],v[nmax],sol;
void back(int);
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]);
    back(1);
    printf("%d ", sol);
    return 0;
}
void back(int k)
{
    int i,j,s,S=0;
    if(k==(n+1))
    {
        for(i=1;i<=m;i++)
        {
            s=0;
            for(j=1;j<=n;j++)
                s+=(a[j][i]*v[j]);
            s>0?S+=s:S+=-s;
        }
        if(S>sol)sol=S;
        return;
    }
    v[k]=1;
    back(k+1);
    v[k]=-1;
    back(k+1);
}