#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\n";
            return 0;
        }
    }
    cout << "No\n";
}