#include<iostream>
#include<cstdio>
#include<vector>

using namespace std;

int n,m;
int a[10000];
int b[10000];
int x[20000];
int v[10000];
vector<int> r[200];

void sou(int pl,int op)
{
	v[pl]=1;
	x[pl]=op;
	
	for (auto i:r[pl])
	{
		if (!v[i])
		  sou(i,1-op);
	}
	
}

int main()
{
	ios::sync_with_stdio(false); cin.tie(0);
	cin>>n>>m;
	for (int i=1; i<=m; i++)
	{
	  cin>>a[i]>>b[i];
	  r[a[i]].push_back(b[i]);
	  r[b[i]].push_back(a[i]);
	}
	for (int i=1; i<=n; i++)
	  x[i]=-1;
	for (int i=1; i<=n; i++)
	{
		if (!v[i])
		{
		  sou(i,0);
	      
	    }
	}  
	int fl=1;
	for (int i=1; i<=m; i++)
	  if (x[a[i]]==x[b[i]])
	    fl=0;
	if (fl)
	  cout<<"Yes\n";
	else
	  cout<<"No\n";
	
	return 0;
}