#include <bits/stdc++.h>
using namespace std;
const int N = 30010;
int n, arb, temp = 1, viz[N];
vector<int> v[N];
void dfs(int);
int main()
{
    cin >> n;
    for(int x, y,  i = 1; i <= n; i++)
    {
        cin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i = 1; i <= n; i++)
        sort(v[i].begin(), v[i].end());
    dfs(1);
    cout << endl << arb;
    return 0;
}
void dfs(int nod)
{
    cout << temp << ' ';
    viz[nod] = 1;
    vector <int> tempv;
    for(auto it: v[nod])
    {
        if(!viz[it])
        {
            tempv.push_back(it);
            viz[it] = 1;
            temp++;
            if(temp == n)
                arb++;
        }
    }
    for(auto vec: tempv)
        dfs(vec);
    for(auto vec: tempv)
        viz[vec] = 0;
    temp -= tempv.size();
    viz[nod] = 0;
}