using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
class Program
{
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[] NMi => ReadLine().Split().Select(c => int.Parse(c) - 1).ToArray();
    static int[][] NMap(int n) => Enumerable.Repeat(0, n).Select(_ => NMi).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, m) = (c[0], c[1]);
        var map = NMap(m);
        var tree = new List<int>[n];
        for (var i = 0; i < tree.Length; ++i) tree[i] = new List<int>();
        foreach (var edge in map)
        {
            tree[edge[0]].Add(edge[1]);
            tree[edge[1]].Add(edge[0]);
        }
        var colors = new int[n];
        for (var i = 0; i < n; ++i)
        {
            if (DFS(i, 1, tree, colors))
            {
                WriteLine("No");
                return;
            }
        }
        WriteLine("Yes");
    }
    static bool DFS(int cur, int color, List<int>[] tree, int[] colors)
    {
        colors[cur] = color;
        foreach (var next in tree[cur])
        {
            if (colors[next] != 0)
            {
                if (colors[cur] == colors[next]) return false;
            }
            else
            {
                if (!DFS(next, -color, tree, colors)) return false;
            }
        }
        return true;
    }
}