#include<iostream>
#include<vector>
#define int long long
#define maxn 50010
using namespace std;
namespace IO{
	int read(){
		int x=0,f=1;char ch=getchar();
		while(ch<'0'||ch>'9'){
			if(ch=='-')f=-f;
			ch=getchar();
		}
		while(ch>='0'&&ch<='9'){
			x=x*10+ch-'0';
			ch=getchar();
		}return x*f;
	}
	void print(int x){
		if(x<0){
			x=-x;
			putchar('-');
		}
		if(x>9)print(x/10);
		putchar(x%10+'0');
	}
}using namespace IO;
int n,m,cnt[maxn],fa[maxn];bool vis[maxn];
vector<int>a,b,e[maxn];
signed main(){
//	freopen("circle.in","r",stdin);
//	freopen("circle.out","w",stdout);
	n=read();m=read();
	for(int i=1;i<=m;i++){
		int u=read(),v=read();
		e[u].push_back(v);
		e[v].push_back(u);
		if(u==1)a.push_back(v);
		if(v==1)a.push_back(u);
	}
	for(auto i:a)for(auto j:e[i]){
		if(vis[j]){
			cnt[j]++;
			continue;
		}cnt[j]++;
		fa[j]=i;
		vis[j]=1;b.push_back(j);
	}
	for(auto i:b){
		for(auto j:e[i]){
			bool t=1;
			if(!vis[j])continue;
			if(cnt[i]>=3||cnt[j]>=3){cout<<"YES";return 0;}
			for(auto k:e[j])if(k==1){t=0;break;}
			for(auto k:e[i])if(k==1){t=0;break;}
			if(cnt[i]==1&&cnt[j]==1&&fa[i]==fa[j])continue;
			if(t){cout<<"YES";return 0;}
		}
	}cout<<"NO";
	return 0;
}