#include<stdio.h>
FILE * f=fopen("flip.in","r");
FILE * g=fopen("flip.out","w");
int a[1000][1000],s[1000],S[1000],i,j,m,n,SUMA;
int main ()
{
	fscanf(f,"%d",&m);
	fscanf(f,"%d",&n);
	for(i=1;i<=m;i++)
	{
		for(j=1;j<=n;j++)
		{
			fscanf(f,"%d",&a[i][j]);
		}
	}
	for(i=1;i<=m;i++)
	{s[i]=0;}
	i=1;
	while(i<=m)
	{
		for(j=1;j<=n;j++)
		{
			s[i]=s[i]+a[i][j];
		}
		i++;
	}
	for(i=1;i<=m;i++)
	{
		if(s[i]<0)
		{s[i]=-1*s[i];}
	}
	for(i=1;i<=n;i++)
	{S[i]=0;}	
	i=1;
	while(i<=n)
	{
		for(j=1;j<=m;j++)
		{
			S[i]=S[i]+a[i][j];
		}
	}
	for(i=1;i<=n;i++)
	{
		if(S[i]<0)
		{S[i]=-1*S[i];}
	}
	SUMA=0;
	for(i=1;i<=m;i++)
	{
		for(j=1;j<=n;j++)
		{
			SUMA=SUMA+a[i][j];	
		}
	}
	fprintf(g,"%d",SUMA);
	fclose(f);
	fclose(g);
	return 0;
}