#include<bits/stdc++.h>
using namespace std;
const int M=50005,N=20005;
int n,m,u[M],v[M],bsl[N],a;
bitset<N>CCF[N],ls;
int main(){
	//freopen("circle.in","r",stdin);
	//freopen("circle.out","w",stdout);
	cin>>n>>m;
	for(int i=1;i<=m;i++){
		scanf("%d%d",&u[i],&v[i]);
		if(u[i]==1)bsl[v[i]]=1;
		if(v[i]==1)bsl[u[i]]=1;
	}
	for(int i=1;i<=m;i++){
		if(bsl[u[i]])CCF[v[i]].set(u[i]);
		if(bsl[v[i]])CCF[u[i]].set(v[i]);
	}
	for(int i=1;i<=m;i++){
		if(u[i]==1||v[i]==1)continue;
		a=bsl[v[i]]+1;
		if(CCF[u[i]].count()<a)continue;
		a=bsl[u[i]]+1;
		if(CCF[v[i]].count()<a)continue;
		a=bsl[v[i]]+bsl[u[i]]+2;
		if((CCF[u[i]]|CCF[v[i]]).count()<a)continue;
		cout<<"YES";
		return 0; 
	}
	cout<<"NO";
	return 0;
}