#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
#include <queue>
#include <map>
#include <cmath>
#include <iomanip>
#include <set>
#include <cstdio>
#include <string>

using namespace std;

int main() {
  int n;
  cin >> n;
  bool ok = false;
  for (int i = 0; i < n; i++) {
    int v, w;
    cin >> v >> w;
    if (w == 1) {
      ok = true;
    }
  }
  cout << (ok ? "Yes" : "No") << endl;
  return 0;
}