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