#define MOD_TYPE 1

#pragma region Macros
#include <bits/stdc++.h>
using namespace std;
/*
#include <boost/multiprecision/cpp_int.hpp>
#include <boost/multiprecision/cpp_dec_float.hpp>
using multiInt = boost::multiprecision::cpp_int;
using lld = boost::multiprecision::cpp_dec_float_100;
*/
/*
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
*/
using ll = long long int;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pld = pair<ld, ld>;
template <typename Q_type>
using smaller_queue = priority_queue<Q_type, vector<Q_type>, greater<Q_type>>;

constexpr ll MOD = (MOD_TYPE == 1 ? (ll)(1e9 + 7) : 998244353);
//constexpr ll MOD = 1;
constexpr int INF = (int)1e9 + 10;
constexpr ll LINF = (ll)4e18;
constexpr double PI = acos(-1.0);
constexpr double EPS = 1e-11;
constexpr int Dx[] = {0, 0, -1, 1, -1, 1, -1, 1, 0};
constexpr int Dy[] = {1, -1, 0, 0, -1, -1, 1, 1, 0};

#define REP(i, m, n) for (ll i = m; i < (ll)(n); ++i)
#define rep(i, n) REP(i, 0, n)
#define REPI(i, m, n) for (int i = m; i < (int)(n); ++i)
#define repi(i, n) REPI(i, 0, n)
#define MP make_pair
#define MT make_tuple
#define YES(n) cout << ((n) ? "YES" : "NO") << "\n"
#define Yes(n) cout << ((n) ? "Yes" : "No") << "\n"
#define possible(n) cout << ((n) ? "possible" : "impossible") << "\n"
#define Possible(n) cout << ((n) ? "Possible" : "Impossible") << "\n"
#define Yay(n) cout << ((n) ? "Yay!" : ":(") << "\n"
#define all(v) v.begin(), v.end()
#define NP(v) next_permutation(all(v))
#define dbg(x) cerr << #x << ":" << x << "\n";

inline void init_main()
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << setprecision(30) << setiosflags(ios::fixed);
}
template <typename T>
inline bool chmin(T &a, T b)
{
  if (a > b)
  {
    a = b;
    return true;
  }
  return false;
}
template <typename T>
inline bool chmax(T &a, T b)
{
  if (a < b)
  {
    a = b;
    return true;
  }
  return false;
}
inline ll CEIL(ll a, ll b)
{
  return (a + b - 1) / b;
}
template <typename A, size_t N, typename T>
inline void Fill(A (&array)[N], const T &val)
{
  fill((T *)array, (T *)(array + N), val);
}
template <typename T, typename U>
constexpr istream &operator>>(istream &is, pair<T, U> &p) noexcept
{
  is >> p.first >> p.second;
  return is;
}
template <typename T, typename U>
constexpr ostream &operator<<(ostream &os, pair<T, U> &p) noexcept
{
  os << p.first << " " << p.second;
  return os;
}
#pragma endregion

template <typename T = ll>
struct Tree
{
  int V;
  using P = pair<int, ll>;
  vector<vector<P>> E;
  vector<int> par;
  vector<int> depth;
  vector<T> dist;
  vector<vector<int>> par_double; //頂点iの2^k個上の頂点

  Tree(int V_) : V(V_)
  {
    E.resize(V);
    par.resize(V);
    depth.resize(V);
    dist.resize(V);
    par_double.resize(V);
    for (int i = 0; i < V; i++)
      par_double[i].resize(25);
  }

  void add_E(int a, int b, T w = T(1), bool direction = false)
  {
    E[a].push_back(make_pair(b, w));
    if (!direction)
      E[b].push_back(make_pair(a, w));
  }

  void dfs(int p, int d, T w)
  {
    for (auto pi : E[p])
    {
      int v = pi.first;
      if (par[p] == v)
        continue;
      par[v] = p;
      depth[v] = d + 1;
      dist[v] = w + pi.second;
      dfs(v, depth[v], dist[v]);
    }
  }

  void make_tree(int root = 0)
  {
    calculated = false;
    fill(begin(par), end(par), -1);
    depth[root] = 0;
    dist[root] = T(0);
    dfs(root, 0, 0);
  }

  bool calculated;
  void calc_double()
  {
    for (int i = 0; i < V; i++)
      par_double[i][0] = par[i];

    for (int k = 0; k < 24; k++)
    {
      for (int i = 0; i < V; i++)
      {
        if (par_double[i][k] == -1)
          par_double[i][k + 1] = -1;
        else
          par_double[i][k + 1] = par_double[par_double[i][k]][k];
      }
    }
  }

  int getLCA(int a, int b)
  {
    if (!calculated)
    {
      calc_double();
      calculated = true;
    }
    if (a == b)
      return a;
    if (depth[a] < depth[b])
      swap(a, b);
    for (int k = 24; k >= 0; k--)
    {
      if (par_double[a][k] != -1 && depth[par_double[a][k]] >= depth[b])
        a = par_double[a][k];
    }
    if (a == b)
      return a;
    for (int k = 24; k >= 0; k--)
    {
      if (par_double[a][k] != -1 && par_double[a][k] != par_double[b][k])
      {
        a = par_double[a][k];
        b = par_double[b][k];
      }
    }
    return par_double[a][0];
  }
};

void solve()
{
  ll n, k;
  cin >> n >> k;
  if (k > n)
  {
    cout << -1 << "\n";
    return;
  }
  Tree<ll> tr(n);
  rep(i, n - 1)
  {
    int a, b;
    cin >> a >> b;
    a--, b--;
    tr.add_E(a, b);
  }
  tr.make_tree(0);
  smaller_queue<ll> que;
  rep(i, n)
  {
    que.push(tr.depth[i]);
  }
  ll ans = 0;
  ll rem = k;

  while (rem > 0)
  {
    ll d = que.top();
    que.pop();
    ans += d;
    rem--;
  }
  cout << ans << "\n";
}

int main()
{
  init_main();
  solve();
}