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