public class Main {
  static int k;
  static int[][] g;
  private static void solve() {
    int n = ni();
    k = ni();
    
    int[] from = new int[n - 1];
    int[] to = new int[n - 1];
    for (int i = 0; i < n - 1; i ++) {
      from[i] = ni() - 1;
      to[i] = ni() - 1;
    }
    g = packU(n, from, to);

    if (k % 2 == 0) {
      int max = 0;
      for (int i = 0; i < n; i ++) {
        int ret = dfs(i, -1, 0, k / 2);
        max = Math.max(ret, max);
      }
      System.out.println(n - max);
    } else {
      int max = 0;
      
      for (int i = 0; i < n; i ++) {
        for (int v : g[i]) {
          if (i < v) {
            int ret1 = dfs(i, v, 0, k / 2);
            int ret2 = dfs(v, i, 0, k / 2);
            max = Math.max(ret1 + ret2, max);
            
          }
        }
      }
      System.out.println(n - max);
    }
  }

  private static int dfs(int now, int pre, int depth, int maxDepth) {
    if (depth > maxDepth) return 0;

    int ret = 1;
    for (int next : g[now]) {
      if (next != pre) {
        ret += dfs(next, now, depth + 1, maxDepth);
      }
    }
    return ret;
  }

  public static int[][] packU(int n, int[] from, int[] to) {
    return packU(n, from, to, from.length);
  }

  public static int[][] packU(int n, int[] from, int[] to, int sup) {
    int[][] g = new int[n][];
    int[] p = new int[n];
    for (int i = 0; i < sup; i++)
      p[from[i]]++;
    for (int i = 0; i < sup; i++)
      p[to[i]]++;
    for (int i = 0; i < n; i++)
      g[i] = new int[p[i]];
    for (int i = 0; i < sup; i++) {
      g[from[i]][--p[from[i]]] = to[i];
      g[to[i]][--p[to[i]]] = from[i];
    }
    return g;
  }
  
  
  public static void main(String[] args) {
    new Thread(null, new Runnable() {
      @Override
      public void run() {
        long start = System.currentTimeMillis();
        String debug = args.length > 0 ? args[0] : null;
        if (debug != null) {
          try {
            is = java.nio.file.Files.newInputStream(java.nio.file.Paths.get(debug));
          } catch (Exception e) {
            throw new RuntimeException(e);
          }
        }
        reader = new java.io.BufferedReader(new java.io.InputStreamReader(is), 32768);
        solve();
        out.flush();
        tr((System.currentTimeMillis() - start) + "ms");
      }
    }, "", 64000000).start();
  }

  private static java.io.InputStream is = System.in;
  private static java.io.PrintWriter out = new java.io.PrintWriter(System.out);
  private static java.util.StringTokenizer tokenizer = null;
  private static java.io.BufferedReader reader;

  public static String next() {
    while (tokenizer == null || !tokenizer.hasMoreTokens()) {
      try {
        tokenizer = new java.util.StringTokenizer(reader.readLine());
      } catch (Exception e) {
        throw new RuntimeException(e);
      }
    }
    return tokenizer.nextToken();
  }

  private static double nd() {
    return Double.parseDouble(next());
  }

  private static long nl() {
    return Long.parseLong(next());
  }

  private static int[] na(int n) {
    int[] a = new int[n];
    for (int i = 0; i < n; i++)
      a[i] = ni();
    return a;
  }

  private static char[] ns() {
    return next().toCharArray();
  }

  private static long[] nal(int n) {
    long[] a = new long[n];
    for (int i = 0; i < n; i++)
      a[i] = nl();
    return a;
  }

  private static int[][] ntable(int n, int m) {
    int[][] table = new int[n][m];
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        table[i][j] = ni();
      }
    }
    return table;
  }

  private static int[][] nlist(int n, int m) {
    int[][] table = new int[m][n];
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        table[j][i] = ni();
      }
    }
    return table;
  }

  private static int ni() {
    return Integer.parseInt(next());
  }

  private static void tr(Object... o) {
    if (is != System.in)
      System.out.println(java.util.Arrays.deepToString(o));
  }
}




Measured memory_bytes: 23764