#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];
long long L[1010], R[1010];
bool ok = true;
void dfs(long long now) {
  for (long long to : E[now]) {
    dfs(to);
    L[now] = max(L[now], L[to]);
    R[now] = max(R[now], R[to]);
  }
  if (X[now] >= R[now])
    R[now] = X[now];
  else if (X[now] >= L[now])
    L[now] = X[now];
  else
    ok = 0;
}
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];
  }
  dfs(0);
  if (ok) {
    cout << "POSSIBLE" << endl;
  } else {
    cout << "IMPOSSIBLE" << endl;
  }
}
