#include<fstream.h>

ifstream f("flip.in");
ofstream o("flip.out");
int main(){int a,b,m[16][16],i,j,s,v[20],n,sw,w[20],c1,c2,poz1,poz2;
f>>a>>b;
for(i=1;i<=b;i++)for(j=1;j<=a;j++)f>>m[i][j];sw=0;
do{if(sw==1)
{if(c1<0&&c1<c2)for(i=1;i<=a;i++)v[poz1][i]=-1*v[poz1][i];
if(c2<0&&c1<c1)for(i=1;i<=b;i++)w[i][poz2]=-1*w[i][poz2];}
for(i=1;i<=b;i++){s=0;{for(j=1;j<=a;j++)s=s+m[i][j];}v[i]=s;}
for(i=1;i<=a;i++){s=0;{for(j=1;j<=b;j++)s=s+m[i][j];}w[i]=s;}
c1=v[1];
for(i=1;i<=b;i++)if(v[i]<=c1)c1=v[i];poz1=i;
c1=w[1];
for(i=1;i<=a;i++)if(w[i]<=c2)c2=w[i];poz2=i;
sw=1;
}while(c1<0||c2<0);


s=0;
for(i=1;i<=b;i++)for(j=1;j<=a;j++)s=s+m[i][j];
o<<s;
return 0;
}