#include<stdio.h>
int a[17][17],s[17],sc[17],m;
inline int abs1(int &x)
{
	if(x<0)
		return -x;
	return x;
}
inline void inverseaza (int l)
{
	for(int j=0;j<m;++j)
		sc[j]-=a[l][j]<<1;
}
int main()
{
	int n,i,j,max=0,mc,q,x,l;
	FILE *in=fopen("flip.in","r"), *out=fopen("flip.out","w");
	fscanf(in,"%d%d",&n,&m);
	for(i=0;i<n;++i)
		for(j=0;j<m;++j)
		{
			fscanf(in,"%d",&a[i][j]);
			s[j]+=a[i][j];
		}
	for(j=0;j<m;++j)
		max+=abs1(s[j]);
	fclose(in);
	q=1<<n;
	for(i=4;i<=q;++i)
	{
		mc=0;
		x=i;
		l=0;
		for(j=0;j<m;++j)
			sc[j]=s[j];
		while(x)
		{
			if(x&1)
				inverseaza(l);
			x>>=1;
			l++;
		}
		for(j=0;j<m;++j)
			mc+=abs1(sc[j]);
		if(mc>max)
			max=mc;
	}
	fprintf(out,"%d\n",max);
	fclose(out);
	return 0;
}