#include<stdio.h>
FILE*fin,*fout;
long int a[17][17],i,j,s,v[18],m,n,smax,t,S;
int main(){
fin=fopen("flip.in","r");
fout=fopen("flip.out","w");
fscanf(fin,"%ld %ld",&n,&m);
for(i=1;i<=n;i++){
   for(j=1;j<=m;j++){fscanf(fin,"%ld",&a[i][j]);}
   

}

while(v[0]!=1){
for(i=m;i>=0&&v[i]!=0;i--){
v[i]=0;
}
v[i]=1;

S=0;
for(t=1;t<=n;t++){
s=0;
for(j=1;j<=m;j++){
if(v[j]){
  s=s-a[t][j];
}
else
	s+=a[t][j];
}
if(s<0)
	S=S-s;

else
	S=S+s;
}
if(S>smax)
	smax=S;
}
fprintf(fout,"%ld",smax);


return 0;}