#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

ifstream in ("salvare.in");
ofstream out ("salvare.out");

const int max_size = 1e3 + 1, INF = 1e9 + 1;

bool estesol[max_size];
int d[max_size], n, m, k;
vector <int> mc[max_size], noduri;

void dfs (int nod, int par)
{
    int mx = 0, mn = INF;
    for (auto f : mc[nod])
    {
        if (f != par)
        {
            dfs(f, nod);
            mx = max(mx, d[f] + 1);
            mn = min(mn, d[f] + 1);
        }
    }
    d[nod] = mx;
    if (d[nod] == m)
    {
        d[nod] = -m - 1;
        noduri.push_back(nod);
    }
    else
    {
        if (mn < 0 && d[nod] < -mn)
        {
            d[nod] = mn;
        }
    }
}

bool check ()
{
    noduri.clear();
    dfs(1, 0);
    if (d[1] > 0)
    {
        noduri.push_back(1);
    }
    return (noduri.size() <= k);
}

int main ()
{
    in >> n >> k;
    for (int i = 1; i < n; i++)
    {
        int x, y;
        in >> x >> y;
        mc[x].push_back(y);
        mc[y].push_back(x);
    }
    int ans = 0, st = 1, dr = n - 1;
    while (st <= dr)
    {
        m = (st + dr) / 2;
        if (check())
        {
            ans = m;
            dr = m - 1;
        }
        else
        {
            st = m + 1;
        }
    }
    out << ans << '\n';
    m = ans;
    bool mata = check();
    for (auto f : noduri)
    {
     //   out << f << " ";
        estesol[f] = 1;
    }
    k -= noduri.size();
    for (int i = 1; i <= n && k > 0; i++)
    {
        if (!estesol[i])
        {
            k--;
            noduri.push_back(i);
        }
    }
    sort(noduri.begin(), noduri.end());
    for (auto f : noduri)
    {
        out << f << " ";
    }
    in.close();
    out.close();
    return 0;
}