#include <iostream>
#include <utility>
#include <stdint.h>
#include <vector>
#include <map>
#include <boost/multiprecision/cpp_int.hpp>

namespace mp = boost::multiprecision;

using namespace std;

using Bint = mp::cpp_int;

int main()
{
  int N;
  cin >> N;

  vector<pair<int,int>> X;
  
  for (int n=0; n<N; ++n) {
    int64_t a, b;
    cin >> a >> b;

    X.push_back(make_pair(a,b));
  }

  multimap<int,int> badPair;
  
  for (int i1=0; i1<N; ++i1) {
    for (int i2=i1+1; i2<N; ++i2) {
      Bint AA = X[i1].first*X[i2].first, BB = X[i1].second*X[i2].second;
      if (AA+BB==0) {
	badPair.emplace(i1,i2);
	badPair.emplace(i2,i1);
      }
    }
  }

  vector<pair<uint64_t,uint64_t>> DP;

  cout << N << endl;

  return 0;
}
