#include <bits/stdc++.h>
using namespace std;
inline int read() {
  int x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = x * 10 + ch - '0';
    ch = getchar();
  }
  return x * f;
}
struct edge {
  int v, next;
} vs[2010];
int st[2010], ee, n, val[2010], Fs[2010];
int wss[1010][6010], tmp[6010], fg;
inline void addedge(int u, int v) {
  vs[++ee].v = v;
  vs[ee].next = st[u];
  st[u] = ee;
}
inline void dfs(int rt) {
  memset(wss[rt], -1, sizeof wss[rt]);
  wss[rt][0] = 0;
  for (int i = st[rt]; i; i = vs[i].next) {
    dfs(vs[i].v);
    int v = vs[i].v;
    memset(tmp, -1, sizeof tmp);
    for (int i = 5000; i >= val[v]; i--)
      if (wss[rt][i - val[v]] != -1) {
        if (tmp[i] == -1)
          tmp[i] = wss[rt][i - val[v]] + Fs[v];
        else
          tmp[i] = min(tmp[i], wss[rt][i - val[v]] + Fs[v]);
      }
    for (int i = 5000; i >= Fs[v]; i--)
      if (wss[rt][i - Fs[v]] != -1) {
        if (tmp[i] == -1)
          tmp[i] = wss[rt][i - Fs[v]] + val[v];
        else
          tmp[i] = min(tmp[i], wss[rt][i - Fs[v]] + val[v]);
      }
    for (int i = 0; i <= 5000; i++) wss[rt][i] = tmp[i];
  }
  Fs[rt] = 0x3fffffff;
  for (int i = 0; i <= val[rt]; i++)
    if (wss[rt][i] != -1) Fs[rt] = min(Fs[rt], wss[rt][i]);
  if (Fs[rt] == 0x3fffffff) fg = 1;
}
int main() {
  n = read();
  for (int i = 2; i <= n; i++) {
    int k = read();
    addedge(k, i);
  }
  for (int i = 1; i <= n; i++) val[i] = read();
  dfs(1);
  if (fg)
    puts("IMPOSSIBLE");
  else
    puts("POSSIBLE");
  return 0;
}
