#include <bits/stdc++.h>
#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
constexpr int INF = INT_MAX;
constexpr long long LINF = LLONG_MAX;
constexpr double eps = 1e-9;
template <class T>
class prique : std::priority_queue<T, std::vector<T>, std::greater<T>> {};
template <class T, class Alloc = std::allocator<T>>
class Vector {
  using traits = std::allocator_traits<Alloc>;

 public:
  using value_type = T;
  using allocator_type = Alloc;
  using size_type = unsigned int;
  using difference_type = int;
  using reference = T&;
  using const_reference = const T&;
  using pointer = typename traits::pointer;
  using const_pointer = typename traits::const_pointer;
  class iterator {
   public:
    using difference_type = int;
    using value_type = Vector::value_type;
    using pointer = Vector::pointer;
    using reference = Vector::reference;
    using iterator_category = std::random_access_iterator_tag;

   private:
    pointer p;

   public:
    iterator() noexcept : p() {}
    iterator(const Vector& base, difference_type index) noexcept
        : p(base.e + index) {}
    iterator(const iterator& i) : p(i.p) {}
    iterator& operator=(const iterator& i) = default;
    iterator& operator=(iterator&& i) noexcept = default;
    iterator& operator++() {
      p++;
      return *this;
    }
    iterator operator++(int) {
      iterator res = *this;
      p++;
      return res;
    }
    iterator operator+(const difference_type& x) const {
      iterator res = *this;
      return res += x;
    }
    iterator& operator+=(const difference_type& x) {
      p += x;
      return *this;
    }
    iterator& operator--() {
      p--;
      return *this;
    }
    iterator operator--(int) {
      iterator res = *this;
      p--;
      return res;
    }
    iterator operator-(const difference_type x) const {
      iterator res = *this;
      return res -= x;
    }
    difference_type operator-(const iterator& i) const { return p - i.p; }
    iterator& operator-=(const difference_type x) {
      p -= x;
      return *this;
    }
    reference operator*() const { return *p; }
    reference operator[](const difference_type x) const { return *(p + x); }
    bool operator<(const iterator& i) const { return p < i.p; }
    bool operator<=(const iterator& i) const { return p <= i.p; }
    bool operator==(const iterator& i) const { return p == i.p; }
    bool operator>(const iterator& i) const { return p > i.p; }
    bool operator>=(const iterator& i) const { return p >= i.p; }
    bool operator!=(const iterator& i) const { return p != i.p; }
  };
  class const_iterator {
   public:
    using difference_type = int;
    using value_type = Vector::value_type;
    using pointer = const Vector::pointer;
    using reference = const Vector::reference;
    using iterator_category = std::random_access_iterator_tag;

   private:
    pointer p;

   public:
    const_iterator() noexcept : p() {}
    const_iterator(const Vector& base, difference_type index) noexcept
        : p(base.e + index) {}
    const_iterator(const const_iterator& i) : p(i.p) {}
    const_iterator& operator=(const const_iterator& i) noexcept = default;
    const_iterator& operator=(const_iterator&& i) noexcept = default;
    const_iterator& operator++() {
      p++;
      return *this;
    }
    const_iterator operator++(int) {
      const_iterator res = *this;
      p++;
      return res;
    }
    const_iterator operator+(const difference_type x) const {
      const_iterator res = *this;
      return res += x;
    }
    const_iterator& operator+=(const difference_type x) {
      p += x;
      return *this;
    }
    const_iterator& operator--() {
      p--;
      return *this;
    }
    const_iterator operator--(int) {
      const_iterator res = *this;
      p--;
      return res;
    }
    const_iterator operator-(const difference_type x) const {
      const_iterator res = *this;
      return res -= x;
    }
    difference_type operator-(const const_iterator& i) const { return p - i.p; }
    const_iterator& operator-=(const difference_type x) {
      p -= x;
      return *this;
    }
    reference operator*() const { return *p; }
    reference operator[](const difference_type x) const { return *(p + x); }
    bool operator<(const const_iterator& i) const { return p < i.p; }
    bool operator<=(const const_iterator& i) const { return p <= i.p; }
    bool operator==(const const_iterator& i) const { return p == i.p; }
    bool operator>(const const_iterator& i) const { return p > i.p; }
    bool operator>=(const const_iterator& i) const { return p >= i.p; }
    bool operator!=(const const_iterator& i) const { return p != i.p; }
  };
  using reverse_iterator = std::reverse_iterator<iterator>;
  using const_reverse_iterator = std::reverse_iterator<const_iterator>;

 private:
  pointer e;
  size_type length = 0, cap = 1;
  Alloc alloc;
  static_assert(
      std::is_same<T, typename Alloc::value_type>::value,
      "The allocator value type is not matched the vector value type.");
  static_assert(!std::is_const<T>::value,
                "This library forbids containers of const elements");

 public:
  Vector() : Vector(Alloc()) {}
  explicit Vector(const Alloc& a) noexcept : alloc(a) {
    e = alloc.allocate(cap);
  }
  explicit Vector(size_type n, const Alloc& a = Alloc()) : alloc(a) {
    while (cap < n) cap *= 2;
    e = alloc.allocate(cap);
    for (int i = 0; i < (int)(n); i++) emplace_back();
  }
  explicit Vector(size_type n, const_reference value, const Alloc& a = Alloc())
      : alloc(a) {
    while (cap < n) cap *= 2;
    e = alloc.allocate(cap);
    for (int i = 0; i < (int)(n); i++) emplace_back(value);
  }
  template <class InputIter>
  Vector(InputIter first, InputIter last, const Alloc& a = Alloc()) : alloc(a) {
    e = alloc.allocate(cap);
    for (InputIter i = first; i != last; i++) {
      emplace_back(*i);
    }
  }
  Vector(const Vector& x, const Alloc& a = Alloc()) : alloc(a) {
    while (cap < x.length) cap *= 2;
    length = x.length;
    e = alloc.allocate(cap);
    for (int i = 0; i < (int)(x.length); i++)
      traits::construct(alloc, e + i, *(x.e + i));
  }
  Vector(Vector&& x, const Alloc& a = Alloc()) : alloc(a) {
    cap = x.cap;
    length = x.length;
    e = x.e;
    x.e = nullptr;
  }
  ~Vector() {
    if (e != nullptr) {
      for (int i = 0; i < (int)(length); i++) traits::destroy(alloc, e + i);
      alloc.deallocate(e, cap);
    }
  }
  Vector& operator=(const Vector& x) {
    for (int i = 0; i < (int)(length); i++) traits::destroy(alloc, e + i);
    alloc.deallocate(e, cap);
    length = x.length;
    cap = 1;
    while (cap < length) cap *= 2;
    e = alloc.allocate(cap);
    for (int i = 0; i < (int)(length); i++)
      traits::construct(alloc, e + i, *(x.e + i));
    return *this;
  }
  Vector& operator=(Vector&& x) {
    for (int i = 0; i < (int)(length); i++) traits::destroy(alloc, e + i);
    alloc.deallocate(e, cap);
    cap = x.cap;
    length = x.length;
    e = x.e;
    x.e = nullptr;
    return *this;
  }

 private:
  void extension() {
    pointer e_ = alloc.allocate(cap * 2);
    for (int i = 0; i < (int)(length); i++)
      traits::construct(alloc, e_ + i, *(e + i));
    for (int i = 0; i < (int)(length); i++) traits::destroy(alloc, e + i);
    alloc.deallocate(e, cap);
    e = e_;
    cap *= 2;
  }
  void extension(size_type n) {
    unsigned int r = 1;
    while (cap * r < n) r *= 2;
    if (r == 1) return;
    pointer e_ = alloc.allocate(cap * r);
    for (int i = 0; i < (int)(length); i++)
      traits::construct(alloc, e_ + i, *(e + i));
    for (int i = 0; i < (int)(length); i++) traits::destroy(alloc, e + i);
    alloc.deallocate(e, cap);
    e = e_;
    cap *= r;
  }

 public:
  template <class InputIter>
  void assign(InputIter first, InputIter last) {
    size_type cnt = 0;
    for (InputIter i = first; i != last; i++) {
      if (cnt == cap) {
        length = std::max(length, cnt);
        extension();
      }
      traits::construct(alloc, e + cnt, *i);
      cnt++;
    }
  }
  void assign(size_type n, const_reference value) {
    extension(n);
    std::fill(e, e + n, value);
  }
  template <class... Args>
  void emplace_back(Args&&... args) {
    if (length == cap) extension();
    traits::construct(alloc, e + length, std::forward<Args>(args)...);
    length++;
  }
  void push_back(const_reference value) { emplace_back(value); }
  void push_back(T&& value) { emplace_back(std::move(value)); }
  void pop_back() {
    traits::destroy(alloc, e + length);
    length--;
  }
  void reserve(size_type n) { extension(n); }
  iterator erase(iterator pos) {
    const iterator res = pos;
    iterator t = pos;
    t++;
    for (iterator i = pos; t != end(); i++, t++) {
      *i = std::move(*t);
    }
    pop_back();
    return res;
  }
  iterator erase(iterator first, iterator last) {
    const iterator res = first;
    typename iterator::difference_type d = last - first;
    for (iterator i = first; i + d != end(); i++) {
      *i = std::move(*(i + d));
    }
    for (int i = 0; i < (int)(d); i++) pop_back();
    return res;
  }
  void swap(Vector& x) {
    std::swap(length, x.length);
    std::swap(cap, x.cap);
    std::swap(e, x.e);
  }
  void clear() {
    while (length) pop_back();
  }
  size_type size() const { return length; }
  void resize(size_type n, const_reference value = T()) {
    extension(n);
    while (n < length) pop_back();
    std::fill(e, e + n, value);
  }
  size_type capacity() const { return cap; }
  bool empty() const { return !length; }
  reference operator[](const size_type pos) { return e[pos]; }
  pointer data() { return e; }
  reference front() { return *e; }
  reference back() { return *(e + length - 1); }
  iterator begin() noexcept { return iterator(*this, 0); }
  const_iterator begin() const noexcept { return const_iterator(*this, 0); }
  const_iterator cbegin() const noexcept { return const_iterator(*this, 0); }
  iterator rbegin() noexcept { return reverse_iterator(*this, 0); }
  const_iterator rbegin() const noexcept {
    return const_reverse_iterator(*this, 0);
  }
  const_iterator crbegin() const noexcept {
    return const_reverse_iterator(*this, 0);
  }
  iterator end() noexcept { return iterator(*this, length); }
  const_iterator end() const noexcept { return const_iterator(*this, length); }
  const_iterator cend() const noexcept { return const_iterator(*this, length); }
  iterator rend() noexcept { return reverse_iterator(*this, length); }
  const_iterator rend() const noexcept {
    return const_reverse_iterator(*this, length);
  }
  const_iterator crend() const noexcept {
    return const_reverse_iterator(*this, length);
  }
};
template <class T, class U>
inline bool chmax(T& lhs, const U& rhs) {
  if (lhs < rhs) {
    lhs = rhs;
    return 1;
  }
  return 0;
}
template <class T, class U>
inline bool chmin(T& lhs, const U& rhs) {
  if (lhs > rhs) {
    lhs = rhs;
    return 1;
  }
  return 0;
}
inline long long gcd(long long a, long long b) {
  while (b) {
    long long c = a;
    a = b;
    b = c % b;
  }
  return a;
}
inline long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
bool isprime(long long n) {
  if (n == 1) return false;
  for (int i = 2; i * i <= n; i++) {
    if (n % i == 0) return false;
  }
  return true;
}
long long mypow(long long a, long long b) {
  if (!b) return 1;
  if (b & 1) return mypow(a, b - 1) * a;
  long long memo = mypow(a, b >> 1);
  return memo * memo;
}
long long modpow(long long a, long long b, long long m) {
  if (!b) return 1;
  if (b & 1) return modpow(a, b - 1, m) * a % m;
  long long memo = modpow(a, b >> 1, m);
  return memo * memo % m;
}
template <typename T>
void printArray(std::vector<T>& vec) {
  for (int i = 0; i < (int)(vec.size() - 1); i++) std::cout << vec[i] << " ";
  std::cout << vec.back() << std::endl;
}
template <typename T>
void printArray(Vector<T>& vec) {
  for (int i = 0; i < (int)(vec.size() - 1); i++) std::cout << vec[i] << " ";
  std::cout << vec.back() << std::endl;
}
template <typename T>
void printArray(T l, T r) {
  T rprev = r;
  rprev--;
  for (T i = l; i != rprev; i++) {
    std::cout << *i << " ";
  }
  std::cout << *rprev << std::endl;
}
std::string to_string(Vector<int>& vec) {
  std::string res = "[";
  for (int i = 0; i < (int)(vec.size() - 1); i++)
    res += std::to_string(vec[i]) + ", ";
  res += std::to_string(vec.back()) + "]";
  return res;
}
int n, parent, x[1010], dp1[1010];
Vector<int> vec[1010];
bool isleaf[1010], dp2[5010];
void func(int node) {
  int sum = 0;
  for (int i : vec[node]) {
    func(i);
    sum += std::min(x[i], dp1[i]);
  }
  if (sum > x[node]) {
    puts("IMPOSSIBLE");
    exit(0);
  }
  std::fill(dp2, dp2 + 5001, false);
  dp2[0] = true;
  for (int i : vec[node]) {
    sum += std::max(x[i], dp1[i]);
    for (int j = 5001; j >= 0; j--) {
      dp2[std::min(5001, j + x[i])] |= dp2[j];
      dp2[std::min(5001, j + dp1[i])] |= dp2[i];
    }
  }
  for (int j = std::max(0, sum - x[node]); j <= 5001; j++) {
    if (dp2[j]) {
      dp1[node] = j;
      return;
    }
  }
}
int main() {
  std::cin >> n;
  std::fill(isleaf + 1, isleaf + n + 1, true);
  for (int i = 2; i <= n; i++) {
    std::cin >> parent;
    vec[parent].push_back(i);
    isleaf[parent] = false;
  }
  for (int i = 1; i <= (int)(n); i++) std::cin >> x[i];
  std::fill(dp1 + 1, dp1 + n + 1, 5001);
  for (int i = 1; i <= (int)(n); i++) {
    if (isleaf[i]) dp1[i] = 0;
  }
  func(1);
  puts("POSSIBLE");
  return 0;
}
