#include <bits/stdc++.h>
using namespace std;
const long long INFL = 1LL << 60;
const int INF = 1 << 30;
long long MOD = 1000000007;
vector<long long> dy = {0, 0, 1, -1, 1, 1, -1, -1, 0};
vector<long long> dx = {1, -1, 0, 0, 1, -1, 1, -1, 0};
void BinarySay(long long x, long long y = 60) {
  for (long long i = 0; i < (y); i++) cout << (x >> (y - 1 - i) & 1);
  cout << endl;
}
long long pow_long(long long x, long long k) {
  long long res = 1;
  while (k > 0) {
    if (k % 2) res *= x;
    x *= x;
    k /= 2;
  }
  return res;
}
long long pow_mod(long long x, long long k) {
  long long res = 1;
  while (k > 0) {
    if (k % 2) {
      res *= x;
      res %= MOD;
    }
    x *= x;
    x %= MOD;
    k /= 2;
  }
  return res;
}
long long inverse(long long x) { return pow_mod(x, MOD - 2); };
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long lcm(long long x, long long y) { return x / gcd(x, y) * y; };
long long kai_mod(long long x) {
  if (x == 0) return 1;
  return x * kai_mod(x - 1) % MOD;
}
const int MAXcomb = 200010;
long long fac[MAXcomb], finv[MAXcomb], inv[MAXcomb];
void COMinit() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  inv[1] = 1;
  for (int i = 2; i < MAXcomb; i++) {
    fac[i] = fac[i - 1] * i % MOD;
    inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    finv[i] = finv[i - 1] * inv[i] % MOD;
  }
}
long long comb(int n, int k) {
  if (n < k) return 0;
  if (n < 0 || k < 0) return 0;
  return fac[n] * finv[k] % MOD * finv[n - k] % MOD;
}
long long N;
long long Par[1010];
vector<long long> E[1010];
long long X[1010];
vector<set<pair<long long, long long>>> WB(1010);
bool dfs(long long now) {
  for (long long to : E[now]) {
    if (dfs(to) == 0) return 0;
  }
  set<pair<long long, long long>> a, b;
  a.insert({0, 0});
  for (long long to : E[now]) {
    for (auto itr1 = WB[to].begin(); itr1 != WB[to].end(); itr1++) {
      for (auto itr2 = a.begin(); itr2 != a.end(); itr2++) {
        pair<long long, long long> p = *itr1, q = *itr2;
        q.first += p.first;
        q.second += p.second;
        if (q.first > X[now] && q.second > X[now]) continue;
        b.insert(q);
      }
    }
    a = b;
    b.clear();
  }
  for (auto itr = a.begin(); itr != a.end(); itr++) {
    pair<long long, long long> p = *itr, q = *itr;
    if (p.first <= X[now]) {
      p.first = X[now];
      b.insert(p);
    }
    if (q.second <= X[now]) {
      q.second = X[now];
      b.insert(q);
    }
  }
  WB[now] = b;
  return b.size();
}
int main() {
  cin >> N;
  for (long long i = 0; i < (N); i++) {
    if (i == 0) continue;
    cin >> Par[i];
    Par[i]--;
    E[Par[i]].push_back(i);
  }
  for (long long i = 0; i < (N); i++) {
    cin >> X[i];
  }
  if (dfs(0)) {
    cout << "POSSIBLE" << endl;
  } else {
    cout << "IMPOSSIBLE" << endl;
  }
}
