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

#define rep(i, n) for( ll i = 0; i < n; i++ )
using ll = long long;

int main() {
	int x1, y1, x2, y2, x3;
	cin >> x1 >> y1 >> x2 >> y2 >> x3;
	string ans = "No";
	if(y1 == y2) ans = "Yes";
	cout << ans << endl;
}