#include <bits/stdc++.h>
using namespace std;
int main(){
  int N;
  cin >> N;
  vector<int> v(N), w(N);
  for (int i = 0; i < N; i++){
    cin >> v[i] >> w[i];
  }
  bool ok = false;
  for (int i = 0; i < N; i++){
    if (w[i] == 1){
      ok = true;
    }
  }
  if (ok){
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
}