#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint1000000007;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000000000000
	

int main(){	
	
	int N;
	cin>>N;
	
	vector<int> x(N),y(N);
	vector<vector<int>> inds(20003);
	
	vector<int> dy,dx;
	for(int i=-19;i<=19;i++){
		dy.push_back(i);
		rep(j,10000){
			if(i*i + j*j >= 400){
				dx.push_back(j-1);
				break;
			}
		}
	}
	rep(i,N){
		cin>>x[i]>>y[i];
		bool f = true;
		rep(j,dy.size()){
			int xx = x[i] + dy[j];
			if(xx<0||xx>=20002)continue;
			int d = distance(inds[xx].begin(),lower_bound(inds[xx].begin(),inds[xx].end(),y[i]-dx[j]));
			
			if(d==inds[xx].size())continue;
			if(inds[xx][d]>y[i]+dx[j])continue;
			f = false;
			break;
		}
		if(f){
			int d = distance(inds[x[i]].begin(),lower_bound(inds[x[i]].begin(),inds[x[i]].end(),y[i]));
			inds[x[i]].insert(inds[x[i]].begin()+d,y[i]);
		}
		
	}
	int ans = 0;
	rep(i,inds.size())ans += inds[i].size();
	
	cout<<ans<<endl;
	
	return 0;
	
}