#include<iostream>
#include<stdio.h>
long int a[17][17],max;
unsigned short m,n;short st[17];
FILE *f,*g;
void suma()
{ unsigned short i,j;
  long s=0,s1;
 for(j=1;j<=n;j++)
 {
     s1=0;
     for(i=1;i<=m;i++)
         s1+=a[i][j]*st[i];
     s=(s1>0)?(s+s1):(s-s1);
 }
 max=(max>s)?max:s;
}
void back(int p)
{
    int i;
    for(i=-1;i<=1;i+=2)
    {
        st[p]=i;
        if(p==m)
            suma();
        else
            back(p+1);
    }
}
int main()
{   max=0;
    f=fopen("flip.in","r");
    g=fopen("flip.out","w");
    fscanf(f,"%d %d\n",&m,&n);
    for(unsigned short i=1;i<=m;i++)
        for(unsigned short j=1;j<=n;j++)
            fscanf(f,"%ld",&a[i][j]),max+=a[i][j];
    back(1);
    fprintf(g,"%ld",max);
    return 0;
}