#include<bits/stdc++.h>
using namespace std;
using Int = long long;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}


//INSERT ABOVE HERE
signed main(){
  Int n;
  cin>>n;

  auto calc=[&](Int x,Int y){return (x+1000)*30000+(y+1000);};
  unordered_set<Int> sp;

  using P = pair<Int,Int>;
  vector<P> dz;
  for(Int i=-100;i<=100;i++)
    for(Int j=-100;j<=100;j++)
      if(i*i+j*j<400) dz.emplace_back(i,j);
  
  Int cnt=0;
  for(Int i=0;i<n;i++){
    Int x,y;
    cin>>x>>y;

    Int flg=0;    
    for(auto p:dz)
      flg|=sp.count(calc(x+p.first,y+p.second));
      
    if(flg) continue;
    cnt++;
    sp.emplace(calc(x,y));
  }
  
  cout<<cnt<<endl;
  return 0;
}