#include <bits/stdc++.h>
#define Nmax 1005
#define INF 1000000000
#define pb push_back

using namespace std;

vector <int> L[Nmax],ans,v;
int n,k,d[Nmax];
bool viz[Nmax];

inline void Dfs(int nod, int tata, int D)
{
    int neg=INF,poz=-1;
    for(auto it : L[nod])
        if(it!=tata)
        {
            Dfs(it,nod,D);
            if(d[it]<0) neg=min(neg,d[it]);
            else poz=max(poz,d[it]);
        }

    if(poz==-1)
    {
        if(neg==INF) d[nod]=0;
        else d[nod]=neg+1;
    }
    else
    {
        if(poz+1 <= -neg-2) d[nod]=neg+1;
        else d[nod]=poz+1;
    }

    if(d[nod]==D || (!tata && d[nod]>=0))
    {
        v.pb(nod);
        d[nod]=-(D+1);
    }
}

int main()
{
    int i,x,y;
    ifstream cin("salvare.in");
    ofstream cout("salvare.out");
    cin>>n>>k;
    for(i=1;i<n;++i)
    {
        cin>>x>>y;
        L[x].pb(y); L[y].pb(x);
    }
    int st=0,dr=n-1,mij,sol;
    while(st<=dr)
    {
        mij=((st+dr)>>1);
        v.clear();
        Dfs(1,0,mij);
        if(v.size()<=k)
        {
            sol=mij;
            ans=v;
            dr=mij-1;
        }
        else st=mij+1;
    }

    cout<<sol<<"\n";
    for(auto it : ans) viz[it]=1;
    for(i=1;i<=n && ans.size()<k;++i)
        if(!viz[i]) ans.pb(i);
    sort(ans.begin(),ans.end());
    for(auto it : ans) cout<<it<<" ";
    cout<<"\n";
    return 0;
}