#include<stdio.h>
int v[17][17],a[17][17],m,n,i,j,k,q,s,max;
int main()
{
	freopen("flip.in","r",stdin);
	freopen("flip.out","w",stdout);
	scanf("%d%d",&m,&n);
	for(i=0;i<m;++i)
		for(j=0;j<n;++j)
			scanf("%d",&v[i][j]);
	max=-1;
	for(q=0;q<(1<<m);++q)
	{
		s=0;
		
		for(i=0;i<m;++i)
			if((1<<i) & q )
			{
				for(j=0;j<n;++j)
					a[i][j]=-v[i][j];
			}
			else
			{
				for(j=0;j<n;++j)
					a[i][j]=v[i][j];
			}
		for(j=0;j<n;++j)
		{
			k=0;
			for(i=0;i<m;++i)k+=a[i][j];
			s+=(k>0?k:-k);
		}
		
		if(s>max)max=s;
	}
	printf("%d",max);
	return 0;
}