#include <bits/stdc++.h>

#define FOR(i,a,b) for(int i= (a); i<((int)b); ++i)
#define RFOR(i,a) for(int i=(a); i >= 0; --i)
#define FOE(i,a) for(auto i : a)
#define ALL(c) (c).begin(), (c).end()
#define RALL(c) (c).rbegin(), (c).rend()
#define DUMP(x)  cerr << #x << " = " << (x) << endl;
#define SUM(x) std::accumulate(ALL(x), 0LL)
#define MIN(v) *std::min_element(v.begin(), v.end())
#define MAX(v) *std::max_element(v.begin(), v.end())
#define EXIST(v,x) (std::find(v.begin(), v.end(), x) != v.end())
#define BIT(n) (1LL<<(n))
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end());

typedef long long LL;
template<typename T> using V = std::vector<T>;
template<typename T> using VV = std::vector<std::vector<T>>;
template<typename T> using VVV = std::vector<std::vector<std::vector<T>>>;

template<class T> inline T ceil(T a, T b) { return (a + b - 1) / b; }
template<class T> inline void print(T x) { std::cout << x << std::endl; }
template<class T> inline void print_vec(const std::vector<T> &v) { for (int i = 0; i < v.size(); ++i) {  if (i != 0) {std::cout << " ";} std::cout << v[i];} std::cout << "\n"; }
template<class T> inline bool inside(T y, T x, T H, T W) {return 0 <= y and y < H and 0 <= x and x < W; }
template<class T> inline double euclidean_distance(T y1, T x1, T y2, T x2) { return sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)); }
template<class T> inline double manhattan_distance(T y1, T x1, T y2, T x2) { return abs(x1 - x2) + abs(y1 - y2); }

const int INF = 1L << 30;
const double EPS = 1e-9;
const std::string YES = "YES", Yes = "Yes", NO = "NO", No = "No";
const std::vector<int> dy4 = { 0, 1, 0, -1 }, dx4 = { 1, 0, -1, 0 };    // 4近傍（右, 下, 左, 上）
const std::vector<int> dy8 = { 0, -1, 0, 1, 1, -1, -1, 1 }, dx8 = { 1, 0, -1, 0, 1, 1, -1, -1 };

using namespace std;


pair<LL, LL> dfs(LL node, vector<vector<LL>> &tree, vector<LL> &X) {

    if (tree[node].size() == 0) {
        return {X[node], 0};
    }

    vector<pair<LL, LL>> v;
    FOE(n, tree[node]) {
        auto p = dfs(n, tree, X);
        if (p.first == -1 or p.second == -1) {
            return make_pair(-1, -1);
        }
        v.emplace_back(p);
    }

    set<pair<LL, LL>> s1;
    s1.insert({0, 0});
    FOE(p1, v) {
        set<pair<LL, LL>> s2;
        FOE(p2, s1) {
            s2.insert({p2.first + p1.first, p2.second + p1.second});
            s2.insert({p2.first + p1.second, p2.second + p1.first});
        }
        s1 = s2;
    }

    pair<LL, LL> best = make_pair(LONG_LONG_MAX, LONG_LONG_MAX);
    FOE(p, s1) {
        if (p.first <= X[node] and p.second < best.second) {
            best = {X[node], p.second};
        }
        if (p.second <= X[node] and p.first < best.second) {
            best = {X[node], p.first};
        }
    }

    if (best.first == LONG_LONG_MAX or best.second == LONG_LONG_MAX) {
        return {-1, -1};
    }
    return best;

};

int main() {
    cin.tie(0);
	ios::sync_with_stdio(false);

	LL N;
	cin >> N;
	vector<vector<LL>> tree(N);
	vector<LL> X(N);

	FOR(i, 0, N - 1) {
	    int p;
	    cin >> p;
	    p--;
	    tree[p].emplace_back(i + 1);
	}
	FOR(i, 0, N) {
	    cin >> X[i];
	}


	auto ans = dfs(0, tree, X);
	if (ans.first == -1 or ans.second == -1 or (ans.first > X[0] and ans.second > X[1])) {
        print("IMPOSSIBLE");
	}
	else {
        print("POSSIBLE");
    }

	return 0;
}

Measured memory_bytes: 7196