#include<fstream.h>
#define I "flip.in"
#define O "flip.out"
int main()
{
long unsigned n,s=0,m,i,j,a[16][16],s1=0;
ifstream f(I);
ofstream g(O);
f>>n>>m;
for(i=1;i<=n;i++){
for(j=1;j<=n;j++){
f>>a[i][j];
s+=a[i][j];
}
if(s<0){
for(j=1;j<=n;j++)
a[i][j]*=-1;
}
s=0;
}
s=0;
for(i=1;i<=n;i++){
for(j=1;j<=n;j++)
s+=a[j][i];
if(s<0)
for(j=1;j<=n;j++){
a[j][i]*=-1;
s1+=a[j][i];
}
else
s1+=s;
s=0;
}
f.close();
g.close();
return 0;
}