#include <fstream>
using namespace std;ifstream f("flip.in");ofstream g("flip.out");long long n,m,i,j,c,s,a,x,v[20][20];int main(){f>>n>>m;for(i=1;i<=n;i++)for(j=1;j<=m;j++)f>>v[i][j];int y=(1<<m)-1;for(c=0;c<=y;c++){a=0;for(i=1;i<=n;i++){s=0;for(j=1;j<=m;j++){if(((c>>(j-1))&1)==1)s+=v[i][j];else s-=v[i][j];}if(s<0)a-=s;else a+=s;}x=max(a,x);}g<<x;}