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

using namespace std;

vector <int> L[Nmax],vec,ans;
int Best[Nmax],Cnt;

inline void Dfs(int nod, int tata, int x)
{
    int maxx=-1,minn=INF;
    for(auto it : L[nod])
    {
        if(it==tata) continue;
        Dfs(it,nod,x);
        maxx=max(maxx,Best[it]);
        minn=min(minn,Best[it]);
    }
    if(maxx+1 <= abs(minn+1) && minn<0) Best[nod]=minn+1;
    else
        if(maxx+1<x && tata) Best[nod]=maxx+1;
        else
        {
            vec.pb(nod); Best[nod]=-x;
        }

}

int main()
{
    int i,x,y,k,n;
    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,mij,sol;
    while(st<=dr)
    {
        mij=((st+dr)>>1);
        vec.clear(); Dfs(1,0,mij);
        if(vec.size()<=k)
        {
            sol=mij; dr=mij-1;
            ans=vec;
        }
        else st=mij+1;
    }
    cout<<sol<<"\n";
    sort(ans.begin(),ans.end());
    for(auto it : ans) cout<<it<<" ";
    cout<<"\n";
    return 0;
}