#include<cstdio>
using namespace std;
long long rez,r,s;
int v[20],i,j,n,m,k,ad,a[20][20],b[20][20];
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]);
              rez+=a[i][j];}

     for (i=1;i<(1<<n);i++)
        {k=1; ad=1;
         while (ad==1 && k<=n)
            { if (v[k]==0)
                 {v[k]=1; ad=0;}
              else
                 {v[k]=0;
                  k++;}}
         for (j=1;j<=n;j++)
            {if (v[j]==1)
                for (k=1;k<=m;k++)
                    b[j][k]=-1*a[j][k];
            else
                for (k=1;k<=m;k++)
                    b[j][k]=a[j][k];}
         r=0;
         for (j=1;j<=m;j++)
            {s=0;
            for (k=1;k<=n;k++)
                s+=b[k][j];
             if (s<0)
                 r+=-1*s;
             else
                 r+=s;}
            if (r>rez)
                rez=r;}
    printf("%lld",rez);

    return 0;
   }