package main

import . "fmt"
import . "sort"

func main() {
	var a [4]int
	for i:=range a[:] {
		Scan(&a[i])
	}
	Ints(a[:])
	for i,x:=range a[1:] {
		if a[i]!=x {
			Println("No")
			return
		}
	}
	Println("Yes")
}