#include<stdio.h>
int mat[16][16],v[16],max,n,m;
void backtracking(int x){
	int i,j,s,a;
	if(x==m){
		s=0;
		for(i=0;i<m;++i){
			a=0;
			for(j=0;j<n;++j)
				if(v[j])
					a+=-mat[i][j];
				else
					a+=mat[i][j];
			if(a>-a)
				s+=a;
			else
				s+=-a;
		}
		if(max<s)
			max=s;
		return ;
	}
	v[x]=0;
	backtracking(x+1);
	v[x]=1;
	backtracking(x+1);
}
int main () {
	freopen("flip.in","r",stdin);
	freopen("flip.out","w",stdout);
	int i,j;
	scanf("%d%d",&m,&n);
	for(i=0;i<m;++i)
		for(j=0;j<n;++j)
			scanf("%d",&mat[i][j]);
	backtracking(0);
	printf("%d\n",max);
	return 0;
}