#include <bits/stdc++.h>

using namespace std;

const int Nmax = 1010;

int n , k , i , ret , nr;
int dist[Nmax];
bool marked[Nmax] , used[Nmax];

vector < int > ans , g[Nmax];

void dfs(int node , int prev , int k)
{
    for (auto &it : g[node])
        if (it != prev)
            dfs(it , node , k);

    dist[node] = 0;
    for (auto &it : g[node])
        if (it != prev)
            dist[node] = max(dist[node] , dist[it] + 1);
    if (dist[node] == k)
        dist[node] = 0, marked[node] = 1;
}

bool check(int dist)
{
    memset(marked , 0 , sizeof(marked));
    dfs(1 , 0 , dist);

    ret = 0;
    for (i = 1; i <= n; ++i)
        if (marked[i]) ret++;

    return (ret <= k);
}

int search_()
{
    int i , j , step;

    for (step = 1; step < n; step <<= 1);

    for (i = n; step; step >>= 1)
        if (i - step > 0 && check(i - step))
        {
            i -= step; nr = ret;
            memcpy(used , marked,  sizeof(marked));
        }

    for (j = 1; j <= n; ++j)
        if (used[j]) ans.push_back(j);
        else if (nr < k) ans.push_back(j), nr++;



    return i;
}

int main()
{
    freopen("salvare.in","r",stdin);
    freopen("salvare.out","w",stdout);

    scanf("%d %d", &n, &k);
    for (i = 1; i < n; ++i)
    {
        int x , y;
        scanf("%d %d", &x, &y);
        g[x].push_back(y);
        g[y].push_back(x);
    }

    printf("%d\n", search_());
    for (auto &it : ans)
        printf("%d ", it);

    return 0;
}