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

int main() {
    int N; cin >> N;
    string result = "No";
    for (int i=0; i<N; i++) {
        int v, w; cin >> v >> w;
        if (w==1) result = "Yes";
    }
    cout << result << endl;
    return 0;
}