#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <functional>
#include <set>
#include <ctime>
#include <random>
#include <chrono>
#include <cassert>
using namespace std;

namespace {
  using Integer = long long; //__int128;
  template<class T> istream& operator >> (istream& is, vector<T>& vec){for(T& val: vec) is >> val; return is;}
  template<class T> istream& operator ,  (istream& is, T& val){ return is >> val;}
  template<class T> ostream& operator << (ostream& os, const vector<T>& vec){for(int i=0; i<vec.size(); i++) os << vec[i] << (i==vec.size()-1?"":" "); return os;}
  template<class T> ostream& operator ,  (ostream& os, const T& val){ return os << " " << val;}

  template<class H> void print(const H& head){ cout << head; }
  template<class H, class ... T> void print(const H& head, const T& ... tail){ cout << head << " "; print(tail...); }
  template<class ... T> void println(const T& ... values){ print(values...); cout << endl; }

  template<class H> void eprint(const H& head){ cerr << head; }
  template<class H, class ... T> void eprint(const H& head, const T& ... tail){ cerr << head << " "; eprint(tail...); }
  template<class ... T> void eprintln(const T& ... values){ eprint(values...); cerr << endl; }

  class range{
    long long start_, end_, step_;
   public:
    struct range_iterator{
      long long val, step_;
      range_iterator(long long v, long long step) : val(v), step_(step) {}
      long long operator * (){return val;}
      void operator ++ (){val += step_;}
      bool operator != (range_iterator& x){return step_ > 0 ? val < x.val : val > x.val;}
    };
    range(long long len) : start_(0), end_(len), step_(1) {}
    range(long long start, long long end) : start_(start), end_(end), step_(1) {}
    range(long long start, long long end, long long step) : start_(start), end_(end), step_(step) {}
    range_iterator begin(){ return range_iterator(start_, step_); }
    range_iterator   end(){ return range_iterator(  end_, step_); }
  };

  string operator "" _s (const char* str, size_t size){ return move(string(str)); }
  constexpr Integer my_pow(Integer x, Integer k, Integer z=1){return k==0 ? z : k==1 ? z*x : (k&1) ? my_pow(x*x,k>>1,z*x) : my_pow(x*x,k>>1,z);}
  constexpr Integer my_pow_mod(Integer x, Integer k, Integer M, Integer z=1){return k==0 ? z%M : k==1 ? z*x%M : (k&1) ? my_pow_mod(x*x%M,k>>1,M,z*x%M) : my_pow_mod(x*x%M,k>>1,M,z);}
  constexpr unsigned long long operator "" _ten (unsigned long long value){ return my_pow(10,value); }

  inline int k_bit(Integer x, int k){return (x>>k)&1;} //0-indexed

  mt19937 mt(chrono::duration_cast<chrono::nanoseconds>(chrono::steady_clock::now().time_since_epoch()).count());

  template<class T> string join(const vector<T>& v, const string& sep){
    stringstream ss; for(int i=0; i<v.size(); i++){ if(i>0) ss << sep; ss << v[i]; } return ss.str();
  }

  string operator * (string s, int k){ string ret; while(k){ if(k&1) ret += s; s += s; k >>= 1; } return ret; }

}

constexpr long long mod = 9_ten + 7;

#include <bitset>
using bits = bitset<2020>;
//using bits = bitset<10>;

void dbg(bits& b){
  cerr << b << endl;
}

int main(){
  int n, k;
  cin >> n, k;
  vector<vector<int>> G (n);
  for(int i=0; i<n-1; i++){
    int a,b;
    cin >> a,b;

    a--; b--;
    G[a].push_back(b);
    G[b].push_back(a);
  }

  int ans = 0;

  vector<bits> bb(n);
  for(int i=0; i<n; i++){
    function<void(int,int, int)> dfs = [&](int pos, int last, int dist){
      bb[i].set(pos);
      if(dist == k) return;
      for(int nx : G[pos]){
        if(nx == last) continue;
        dfs(nx, pos, dist+1);
      }
    };

    dfs(i, i, 0);

    //dbg(bb[i]);
  }

  vector<int> ord(n);
  iota(ord.begin(), ord.end(), 0);
  shuffle(ord.begin(), ord.end(), mt);

  for(int r_=0; r_<min(n,500); r_++){
  //for(int r=0; r<n; r++){
    int r = ord[r_];
    vector<pair<int,int>> dd;
    function<void(int,int,int)> dfs = [&](int pos, int last, int dist){
      if(pos != r) dd.push_back({dist, pos});
      if(dist == k) return;

      for(int nx : G[pos]){
        if(nx == last) continue;
        dfs(nx, pos, dist+1);
      }
    };

    dfs(r, r, 0);
    sort(dd.begin(), dd.end());

    bits s;
    s.set(r);

    for(int i=0; i<dd.size(); i++){
      int j = i;
      s.set( dd[i].second );
      while(j+1<dd.size() && dd[j+1].first == dd[i].first){
        s.set(dd[j+1].second);
        j++;
      }

      //dbg(s);

      while(1){
        //cerr << s << " & " << bb[dd[i].second] << " = " << (s&bb[dd[i].second]).count() << endl;
        ans = max<int>(ans, (s & bb[dd[i].second]).count() );
        if(i==j) break;
        i++;
      }

      i = j;
    }
  }

  println( n - ans );
  return 0;
}


Measured memory_bytes: 1024