#include <bits/stdc++.h>
#define maxN 1005
#define INF (1<<30)
using namespace std;
bool seen[maxN];
int dp[maxN];
vector<int>v[maxN],tempsol,sol;
int n,i,j,x,y,k,dist;
int st,dr,mij,ans;
void dfs(int nod,int tata)
{
    int bst=INF;
    for(vector<int>::iterator it=v[nod].begin();it!=v[nod].end();it++)
        if(*it!=tata)
        {
            dfs(*it,nod);
            dp[nod]=max(dp[nod],dp[*it]+1);
            bst=min(bst,dp[*it]+1);
        }
    if(dp[nod]==dist)
    {
        tempsol.push_back(nod);
        dp[nod]=-dist-1;
        return;
    }
    if(bst<0 && -bst-1>=dp[nod])
        dp[nod]=bst;
}
bool verif(int val)
{
    dist=val;
    memset(dp,0,sizeof(dp));
    tempsol.clear();
    dfs(1,0);
    if(dp[1]>=0)
        tempsol.push_back(1);
    if((int)tempsol.size()<=k)
        return true;
    return false;
}
int main()
{
    freopen("salvare.in","r",stdin);
    freopen("salvare.out","w",stdout);
    scanf("%d%d",&n,&k);
    for(i=1;i<n;i++)
        scanf("%d %d",&x,&y),
        v[x].push_back(y),
        v[y].push_back(x);
    st=0,dr=n;
    while(st<=dr)
    {
        mij=st+(dr-st)/2;
        if(verif(mij))
            ans=mij,sol=tempsol,dr=mij-1;
        else st=mij+1;
    }
    printf("%d\n",ans);
    for(i=0;i<sol.size();i++)
        seen[sol[i]]=true;
    for(i=1;i<=n;i++)
        if(seen[i])
            printf("%d ",i);
        else if(sol.size()<k)
            k--,printf("%d ",i);
    return 0;
}