// No.2515 Similar Triangles
package main

import "fmt"

func main() {
	var x1, y1, x2, y2, x3 int
	fmt.Scan(&x1, &y1, &x2, &y2, &x3)
	if y1 == y2 {
		fmt.Println("Yes")
	} else {
		fmt.Println("No")
	}
}