# -*- coding: utf-8 -*-

import itertools


def mostProperComb(childs, x):
    tmp_sum = sum([c[1] for c in childs])
    if tmp_sum > x:
        print("IMPOSSIBLE")
        exit()

    total = tmp_sum + sum([c[0] for c in childs])

    sset = set([tmp_sum])
    for child in childs:
        rest = child[0] - child[1]
        tmp_set = set(sset)
        for s in sset:
            if s + rest <= x:
                tmp_set.add(s+rest)
        sset = tmp_set

    return (tuple(sorted([x, total-max(sset)], reverse=True)))


n = int(input())

p_list = [0] + list(map(int, input().split()))
x_list = list(map(int, input().split()))
c_list = [[] for i in range(n)]

if n == 1:
    print("POSSIBLE")
    exit()

for i in range(n):
    index = n-1-i

    if len(c_list[index]) == 0:
        c_list[index] = (x_list[index], 0)
        c_list[p_list[index]-1].append(index)
    else:
        childs = [c_list[child_index] for child_index in c_list[index]]
        c_list[index] = mostProperComb(childs, x_list[index])
        if not p_list[index] == 0:
            c_list[p_list[index]-1].append(index)

print("POSSIBLE")
