#include <stdio.h>
#include <limits.h>
#define INF (long long)3000000000
using namespace std;
FILE *f=fopen("flip.in","r"),*g=fopen("flip.out","w");
int a[17][17],i,j,m,n,ok,v[17],s;
long long st;
int main()
{
    long long max= -INF;
    fscanf(f,"%d %d",&n,&m);
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
            fscanf(f,"%d",&a[i][j]);
    ok=1;
    while(ok){
           ok=0;
        for(i=1;i<=n && ok==0;i++)
            if(v[i]==0){
                v[i]=1;
                ok=1;
        }
             else
                v[i]=0;
        if(ok){
            st=0;
            for(j=1;j<=m;j++){
 
                    s=0;
                    for(i=1;i<=n;i++)
                        if(v[i])
                        s=s-a[i][j];
                        else
                          s=s+a[i][j];
                   if(s>0)
                        st+=s;
                    else
                        st+=-s;
            }
               if(st>max)
                        max=st;
                }
    }
    fprintf(g,"%lld",max);
 
    return 0;
}