#include <iostream>
#include <cstdio>
using namespace std;
int n,m,i,j,k,max1,nrsubm,sum,sum1,a[17][17];
int main()
{
    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]);
            max1+=a[i][j];
        }
    nrsubm=1<<n/2;
    for(k=0;k<=nrsubm;k++)
    {
        sum1=0;
        for(i=1;i<=n;i++)
        {
            sum=0;
            for(j=1;j<=m;j++)
                if((k&(1<<(j-1)))!=0)
                    sum-=a[i][j];
                else
                    sum+=a[i][j];
            if(sum<0)
                sum=sum*-1;
            sum1+=sum;
        }
        if(sum1>max1)
            max1=sum1;
    }
    cout<<max1;
    return 0;
}