#include<fstream.h>

ifstream f("flip.in");
ofstream o("flip.out");
int main(){int a,b,m[16][16],i,j,s,c,v[20],n;
f>>a>>b;
for(i=1;i<=b;i++)for(j=1;j<=a;j++)f>>m[b][a];
for(i=1;i<=b;i++){s=0{for(j=1;j<=a;j++)s=s+m[b][a]}v[n]=s;n++;}
c=v[1];
for(i=2;i<=b;i++)if(v[i]>c)c=v[i];
for(i=1;i<=b;i++){if(v[i]==c)for(j=1;j<=a;j++)m[i][j]=-m[i][j];i=b;}
n=1
for(i=1;i<=a;i++){s=0{for(j=1;j<=b;j++)s=s+m[b][a]}v[n]=s;n++;}
c=v[1];
for(i=2;i<=a;i++)if(v[i]>c)c=v[i];
for(i=1;i<=a;i++){if(v[i]==c)for(j=1;j<=b;j++)m[i][j]=-m[i][j];i=a;}
s=0
for(i=1;i<=b;i++)for(j=1;j<=a;j++)s=s+m[b][a];
o<<s;
return 0;
}