#include using namespace std; const int M=50005,N=20005; int n,m,u[M],v[M],bsl[N],a,b; bitsetCCF[N]; 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[u[i]]+bsl[v[i]]+2; b=(CCF[u[i]]|CCF[v[i]]).count(); if(b>=a){ cout<<"YES"; return 0; } } cout<<"NO"; return 0; }