#include <iostream>
#include<fstream>
#define FOR(i,a,b) for(i=a;i<=b;i++)
using namespace std;
ifstream f("flip.in");
ofstream g("flip.out");
int n,m,a[20][20],i,j,s,s2,k,lg,s3;
int main()
{ f>>n>>m;
  FOR(i,1,n)FOR(j,1,m)f>>a[i][j];
  lg=1<<m;
  FOR(k,1,lg){
    s2=0;
      FOR(i,1,n){
        s3=0;
      FOR(j,1,m)
        if(k&(1<<j))s3-=a[i][j];
         else s3+=a[i][j];
      if(s3>-s3)s2+=s3;
      else s2-=s3;}
      if(s2>s)s=s2;
      }
      g<<s;

    return 0;
}