package main

import . "fmt"
import . "os"
import bf "bufio"

func main() {
	rd := bf.NewReader(Stdin)
	var n, m int
	Fscan(rd,&n,&m)
	g := make([][]int, n*2+1)
	for i := 0; i < m; i++ {
		var a, b int
		Fscan(rd,&a,&b)
		g[a] = append(g[a], b+n)
		g[b+n] = append(g[b+n], a)
		g[a+n] = append(g[a+n], b)
		g[b] = append(g[b], a+n)
	}
	visited := make([]int, 2*n+1)
	id := 0
	for i := 1; i <= n; i++ {
		if visited[i] > 0 {
			if visited[i] != visited[i+n] {
				Println("No")
				return
			}
			continue
		}
		id++
		visited[i] = id
		stk := []int{i}
		for len(stk) > 0 {
			l := len(stk)
			p := stk[l-1]
			stk = stk[:l-1]
			for _, e := range g[p] {
				if visited[e] > 0 {
					continue
				}
				visited[e] = id
				stk = append(stk, e)
			}
		}
		if visited[i] != visited[i+n] {
			Println("No")
			return
		}
	}
	Println("Yes")
}