#include<stdio.h>
int m[20][20],sol,v[400],a,b,s,S;
void back(int);
int main()
{
	FILE *f=fopen("flip.in","r");
	FILE *g=fopen("flip.out","w");
	fscanf(f,"%d %d",&a,&b);
	for(int i=1;i<=a;i++)
		for(int j=1;j<=b;j++)
			fscanf(f,"%d",&m[i][j]);
	back(1);
	fprintf(g,"%d",sol);
}
void back(int k)
{
	int S=0,s;
	if(k==(a+1))
	{
		for(int i=1;i<=a;i++)
		{
			s=0;
			for(int j=1;j<=b;j++)
				s+=(m[j][i]*v[j]);
			if(s<0)
				S+=-s;
			else
				S+=s;
		}
		if(S>sol) sol=S;
		return;
	}
	v[k]=1;
	back(k+1);
	v[k]=-1;
	back(k+1);
}