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

void solve() {
    int n;
    cin >> n;
    vector<int> v(n), w(n);
    for (int i = 0; i < n; i++) cin >> v[i] >> w[i];
    if (count(w.begin(), w.end(), 1))
        cout << "Yes" << endl;
    else
        cout << "No" << endl;
}
int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    /*int t;
    cin >> t;
    while (t--)*/
    solve();
}