#include <cstdio>
#include <bitset>
#include <vector>
#include <cstring>
#include <algorithm>
#define DIMN 1001
#define INF 2000000000
using namespace std;
int elem,salv[DIMN],d[DIMN],k,n;
bitset <DIMN> f;
vector <int> v[DIMN];
void dfs (int nod,int x){
    int i,vecin,maxi,mini;
    maxi=0;
    mini=INF;
    f[nod]=1;
    for (i=0;i<v[nod].size();i++){
        vecin=v[nod][i];
        if (f[vecin]==0){
            dfs(vecin,x);
            maxi=max(maxi,d[vecin]+1);
            mini=min(mini,d[vecin]+1);
        }
    }
    d[nod]=maxi;
    if (maxi==x){
        salv[++elem]=nod;
        d[nod]= -x-1;
    }
    else if (mini<0 && 0>=maxi+mini+1){
        d[nod]=mini;
    }
}
int verif (int x){
    elem=0;
    f.reset();
    for (int i=1;i<=n;i++)
        d[i]=0;
    dfs (1,x);
    if (d[1]>=0)
        salv[++elem]=1;
    return elem<=k;
}
int main()
{
    FILE *fin=fopen ("salvare.in","r");
    FILE *fout=fopen ("salvare.out","w");
    int i,x,y,st,dr,mid,add,p;
    fscanf (fin,"%d%d",&n,&k);
    for (i=1;i<n;i++){
        fscanf (fin,"%d%d",&x,&y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    if (k==n){
        fprintf (fout,"0\n");
        for (i=1;i<=n;i++)
            fprintf (fout,"%d ",i);
        return 0;
    }
    st=1;
    dr=n;
    while (st<=dr){
        mid=(st+dr)/2;
        if (verif (mid))
            dr=mid-1;
        else st=mid+1;
    }
    verif (st);
    fprintf (fout,"%d\n",st);
    f.reset();
    for (i=1;i<=elem;i++)
        f[salv[i]]=1;
    add=k-elem;
    p=1;
    while (add){
        if (!f[p]){
            salv[++elem]=p;
            add--;
        }
        p++;
    }
    sort (salv+1,salv+elem+1);
    for (i=1;i<=elem;i++)
        fprintf (fout,"%d ",salv[i]);
    return 0;
}