"""
Google Code Jam Farewell Round C - Problem C

Author  : chaotic_iak
Language: PyPy (Python 3.9.10)
"""

################################################### SOLUTION

def initialize_solution():
    ...

def main():
    N,K = read()
    S = [0] + read()
    P = [0,0] + read()
    child = [[] for _ in range(N+1)]
    for i in range(2,N+1):
        child[P[i]].append(i)

    ans = 0
    for i in range(1,N+1):
        mx = (S[i]-1)//K
        total = sum(S[j] <= mx for j in range(1,N+1))
        totalunder = 0
        dfs = []
        dfs.extend(child[i])
        while dfs:
            p = dfs.pop()
            dfs.extend(child[p])
            if S[p] <= mx: totalunder += 1
        ans += totalunder * (total - totalunder)

    return ans

############################################### PROBLEM TYPE

HAS_TESTCASES = True
INTERACTIVE = False
INTERACTIVE_WRONG_ANSWER = ""

#################################################### HELPERS

import sys

def read_str():
    ipt = input().strip()
    if INTERACTIVE and ipt == INTERACTIVE_WRONG_ANSWER:
        sys.exit()
    return ipt

def read(mapping=int):
    ipt = input().strip()
    if INTERACTIVE and ipt == INTERACTIVE_WRONG_ANSWER:
        sys.exit()
    return list(map(mapping, ipt.split()))

def write_str(obj, end="\n"):
    global OUTPUT
    OUTPUT.append(obj + end)

def write(*obj, sep=" ", end="\n"):
    global OUTPUT
    OUTPUT.append(sep.join(map(str, obj)) + end)

def flush():
    global OUTPUT
    print("".join(OUTPUT), end="", flush=True)
    OUTPUT = []

def solve_testcase():
    result = main()
    if result is not None:
        write(result)

OUTPUT = []
initialize_solution()
if HAS_TESTCASES:
    TOTAL_CASES = int(input())
else:
    TOTAL_CASES = 1
for CASE_NUMBER in range(TOTAL_CASES):
    write("Case #" + str(CASE_NUMBER+1) + ": ", end="")
    solve_testcase()
flush()

READ_FROM_FILE = ""