#include<stdio.h>   
long n,m,a[16][16],st[16],smax;   
void back(int k)   
{   
    int i,j,s,t;   
    if(k==m)   
    { s=0;   
    for(i=0;i<n;++i)   
     {for(t=j=0;j<m;++j)   
      if(st[j]) t+=-a[i][j];   
      else t+=a[i][j];   
  
    s+=t<-t ? -t : t;   
    }   
    if(smax<s) smax=s;   
    return ;   
    }   
    st[k]=0; back(k+1);   
    st[k]=1; back(k+1);   
   }   
int main()   
{   
long i,j;   
    freopen("flip.in","r",stdin);   
    scanf("%ld %ld",&n,&m);   
  
    for(i=0;i<n;++i)   
     for(j=0;j<m;++j)   
     scanf("%ld",a[i]+j);   
  
    back(0);   
    freopen("flip.out","w",stdout);   
    printf("%ld\n",smax);   
  
  
return 0;   
}