#include <bits/stdc++.h>
#define Nmax 1005
using namespace std;

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

int n,k;
list <int> G[Nmax];
queue < pair<int,int> > q;
int nr_ans;
bitset <Nmax> solution;
bitset <Nmax> s;
int d[Nmax],cnt[Nmax];

void set_bitset()
{
    nr_ans=0;
    for(int i=1;i<=n;i++)
    {
        solution[i]=s[i];
        if(s[i]) ++nr_ans;
    }
}

void DFS(int node, int parent, int dist)
{
    for(const auto &it:G[node])
        if(it!=parent)
            DFS(it,node,dist);
    d[node]=Nmax;
    cnt[node]=dist;
    for(const auto &it:G[node])
        if(it!=parent)
        {
            d[node]=min(d[node],d[it]+1);
            cnt[node]=min(cnt[node],cnt[it]-1);
        }
    if(d[node]<=cnt[node]) cnt[node]=Nmax;
    if(!cnt[node])
    {
        s[node]=true;
        d[node]=0;
        cnt[node]=Nmax;
    }
}

bool sol_valid(int dist)
{
    s.reset();
    DFS(1,0,dist);
    int counter=0;
    for(int i=1;i<=n;i++)
        if(s[i]) counter++;
    return counter<=k;
}

int main()
{
    int x,y,i;
    f>>n>>k;
    for(i=1;i<n;i++)
    {
        f>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    int lo=1,hi=n-1,mid,ans=n-1;
    while(lo<=hi)
    {
        mid=(lo+hi)>>1;
        if(sol_valid(mid))
        {
            ans=mid;
            set_bitset();
            hi=mid-1;
        }
        else lo=mid+1;
    }
    g<<ans<<'\n';
    if(nr_ans<k)
    {
        i=1;
        while(nr_ans<k)
        {
            while(solution[i]) i++;
            solution[i]=true;
            nr_ans++;
        }
    }
    for(i=1;i<=n;i++)
        if(solution[i]) g<<i<<' ';

    return 0;
}