#include<stdio.h>
#include<algorithm>
#define N 1001
using namespace std;

struct punct {
	int x,y;
};

punct p[N];
float pan[N*N];
int n,nr,nrr,nrmax;

int main() {
	int i,j;
	freopen("trapez.in","r",stdin);
	freopen("trapez.out","w",stdout);
	scanf("%d",&n);
	for(i=1;i<=n;++i)
		for(j=1;j<=n;++j) if(i!=j) {
			pan[++nr]=(float)(p[j].y - p[i].y)/(p[j].x-p[i].x);
		}
	sort(&pan[1],&pan[nr+1]);
	nrr=1;
	for(i=2;i<=n;++i) {
		if(pan[i]==pan[i-1])
			++nrr;
		else {
			if(nrr>nrmax)
				nrmax=nrr;
			nrr=1;
		}
	}
	if(nrr>nrmax)
		nrmax=nrr;
	printf("%d\n",nrmax);
	return 0;
}