C++ :

#include<cstdio>
#include<algorithm>
#include<vector>
int n,nn;
int u,v,shu,first[1000010];
struct bian
{
    int v,next;
}o[3000010];
inline void add(int u,int v)
{
 	 o[++shu].v=v;
 	 o[shu].next=first[u];
 	 first[u]=shu;
}
bool flag[1000010];
int sum[1000010],max[1000010],ans[1000010];
inline void build(int x)
{
	flag[x]=1;
	for(int i=first[x];i;i=o[i].next)
		if(!flag[o[i].v])
		{
			build(o[i].v);
			sum[x]+=sum[o[i].v];
			if(max[x]<sum[o[i].v])
				max[x]=sum[o[i].v];
		}
	++sum[x];
	if(max[x]<=nn&&n-sum[x]<=nn)
		ans[++ans[0]]=x;
}
int main()
{
	//freopen("tree.in","r",stdin);
	//freopen("tree.out","w",stdout);
	scanf("%d",&n);
	for(int i=1;i<n;++i)
	{
		scanf("%d%d",&u,&v);
		add(u,v);
		add(v,u);
	}
	nn=n>>1;
	build(1);
	if(ans[0])
	{
		std::sort(ans+1,ans+ans[0]+1);
		for(int i=1;i<=ans[0];++i)
		    printf("%d\n",ans[i]);
	}
	else
	    puts("NONE");
//	getchar();
//	getchar();
//	getchar();
//	getchar();
}