#include<fstream.h>   
ifstream f("flip.in");   
ofstream g("flip.out");   
int a[17][17],s,t,x=1,max;   
short n,m,b[18];   
void citire()   
{f>>n>>m;   
 for(short i=1;i<=n;i++)   
     for(short j=1;j<=m;j++)   
         f>>a[i][j];   
}   
void adun()   
{short i=1;   
 while(b[i])   
    b[i++]=0;   
 b[i]++;   
}   
void sume()   
{for(short i=1;i<=n;i++)   
    {s=0;   
     for(short j=1;j<=m;j++)   
         if(b[j])   
             s+=a[i][j];   
         else   
             s-=a[i][j];   
     if(s<0)   
         t-=s;   
     else   
         t+=s;   
    }   
 if(t>max)   
     max=t;   
}   
int main()   
{   
citire();   
int i;   
for(i=1;i<=m;i++)   
 x*=2;   
for(i=1;i<=x;i++)   
{t=0;   
 sume();   
 adun();   
}   
g<<max;   
return 0;   
}