#include<stdio.h>
long n,m,a[16][16],smax;

int main()
{
	freopen("flip.in","r",stdin);
	freopen("flip.out","w",stdout);
	long i,j,k,s,t;
	scanf("%lld%lld",&n,&m);
	for(i=0;i<n;i++)
		for(j=0;j<m;j++)
			scanf("%lld",a[i]+j);
	for(i=0;i<(1<<m);i++)
	{
		s=0;
		for(k=0;k<n;k++)
		{
			for(t=j=0;j<m;j++)
				if(i & (1<<j))
					t+=-a[k][j];
				else
					t+=a[k][j];
			s+= t<-t ? -t : t;
		}
		if(smax<s)
			smax=s;
	}
	printf("%lld",smax);
	return 0;
}