package main

import . "fmt"

func main() {
	var n,m int
	Scan(&n,&m)
	g := make([][]int, n+1)
	for i := 0; i < m; i++ {
		var a, b int
		Scan(&a, &b)
		g[a] = append(g[a], b)
		g[b] = append(g[b], a)
	}
	visited := make([]int, n+1)
	for i := 1; i <= n; i++ {
		if visited[i] == 0 {
			visited[i] = 1
		}
		stk := []int{i}
		for len(stk) > 0 {
			l := len(stk)
			x := stk[l-1]
			stk = stk[:l-1]
			for _, y := range g[x] {
				if visited[y] == visited[x] {
					Println("No")
					return
				} else if visited[y] == 0 {
					visited[y] = 3 - visited[x]
					stk = append(stk, y)
				}
			}
		}
	}
	Println("Yes")
}