#include <stdio.h>
#include <vector>
using namespace std;

vector<int> G[100100];
int N,D[100100],V[100100];

void go(int x, int l)
{
	D[x] = 1;
	for (int y : G[x]) if (y != l){
		go(y,x);
		if (D[y] > 0) D[x] -= D[y];
	}
}

void go2(int x, int l)
{
	for (int y : G[x]) if (y != l){
		int v = D[x];
		if (D[y] > 0) v += D[y];
		if (V[x] > 0) v -= V[x];
		V[y] = v;
		go2(y,x);
	}
}

int main()
{
	scanf ("%d",&N);
	for (int i=1;i<N;i++){
		int x,y; scanf ("%d %d",&x,&y);
		G[x].push_back(y);
		G[y].push_back(x);
	}

	go(1,0);
	go2(1,0);
	vector<int> ans;
	for (int i=1;i<=N;i++){
		int v = D[i];
		if (V[i] > 0) v -= V[i];
		if (v > 0) ans.push_back(i);
	}
	printf ("%d\n",ans.size());
	for (auto x : ans) printf ("%d\n",x);

	return 0;
}