#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  int n;
  cin >> n;
  rep(_, n) {
    int v, w;
    cin >> v >> w;
    if (w == 1) {
      cout << "Yes" << endl;
      return 0;
    }
  }
  cout << "No" << endl;
  return 0;
}