#include <iostream>

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;
    
    return 0;
}