#include<stdio.h>
int s1,s0,i,j,m,n,a[20][20],s;
int main()
{
	freopen("flip.in","r",stdin);
	freopen("flip.out","w",stdout);
	scanf("%d%d",&n,&m);
	for(i=1;i<=n;i++)
		for(j=1;j<=m;j++)
			scanf("%d",&a[i][j]);
	for(i=1;i<=n;i++)
	{
		s0=0;
		s1=0;
		for(j=1;j<=m;j++)
		{
			s0+=a[i][j];
			s1+=a[i][j]-2*a[i][j];
		}
		if(s1>s0)
			for(j=1;j<=m;j++)
				a[i][j]=a[i][j]-2*a[i][j];
	}
	
	for(j=1;j<=m;j++)
	{
		s0=0;
		s1=0;
		for(i=1;i<=n;i++)
		{
			s0+=a[i][j];
			s1+=a[i][j]-2*a[i][j];
		}
		if(s1>s0)
			for(i=1;i<=n;i++)
			{
				a[i][j]=a[i][j]-2*a[i][j];
				s+=a[i][j];
			}
	}
	s=0;
	for(i=1;i<=n;i++)
	{
		for(j=1;j<=m;j++)
			s+=a[i][j];
	}
	printf("%d",s);
	return 0;
}