import sys
sys.setrecursionlimit(10**6)

class Node:
    def __init__(self):
        self.meifangwen = True
        self.the_list = list()

def fun(jiedian, shendu):
    global ans
    global k
    if shendu <= k:
        ans += 1
    jiedian.meifangwen = False
    shiyezi = True
    for xiayijiedian in jiedian.the_list:
        if xiayijiedian.meifangwen:
            shiyezi = False
            fun(xiayijiedian, shendu+1)
    if shiyezi and k > shendu:
        ans += (k - shendu)

n, k = list(map(int, input().split()))
dictionary = {i: Node() for i in range(1, n+1)}

for _ in range(1, n):
    u, v = list(map(int, input().split()))
    dictionary[u].the_list.append(dictionary[v])
    dictionary[v].the_list.append(dictionary[u])

ans = 0
fun(dictionary[1], 0)
print(ans)

题目最大的难点在于Python有递归深度的限制