#include <bits/stdc++.h>

using namespace std;

vector <int> g[1005], ans, v;

int n, k, d[1005];
bool viz[1005];

void dfs(int nod, int tata, int dis) {
    int neg = 1e9, poz = -1;
    for (auto it : g[nod])
        if (it != tata) {
            dfs(it, nod, dis);
            if (d[it] < 0)
                neg = min(neg, d[it]);
            else
                poz = max(poz, d[it]);
        }
    if (poz == -1) {
        if (neg == 1e9) 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] == dis || (!tata && d[nod] >= 0)) {
        v.push_back(nod);
        d[nod] = -(dis + 1);
    }
}
int main() {
    freopen("salvare.in", "r", stdin);
    freopen("salvare.out", "w", stdout);
    scanf("%d %d", &n, &k);
    for (int i = 1; i < n; ++i) {
        int x, y;
        scanf("%d %d", &x, &y);
        g[x].push_back(y);
        g[y].push_back(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;
    }
    printf("%d\n", sol);
    for (auto it : ans)
        viz[it] = 1;
    for (int i = 1; i <= n && ans.size() < k; ++i)
        if (!viz[i])
            ans.push_back(i);
    sort(ans.begin(), ans.end());
    for (auto it : ans)
        printf("%d ", it);
    return 0;
}