#include<bits/stdc++.h>
using namespace std;

int main(){
  int N;
  cin >> N;
  bool flag = false;
  for(int i=0;i<N;i++){
    int v,w;
    cin >> v >> w;
    if(w == 1) flag = true;
  }
  if(flag) cout << "Yes" << endl;
  else cout << "No" << endl;
}