#include<cstdio>
#include<cstring>
#include<cmath>
#include<cstdlib>
#include<algorithm>
using namespace std;
const int inf=1e9;

int n,x[1005],y[1005];

int head[1005],tot,pre[1005],to[1005];
void addedge(int u,int v) {to[++tot]=v;pre[tot]=head[u];head[u]=tot;}

int dp[5005];
bool o;
void dfs(int u) 
{
	for (int i=head[u];i;i=pre[i]) dfs(to[i]);
	
	for (int i=1;i<=x[u];i++) dp[i]=inf;
	dp[0]=0;
	for (int i=head[u];i;i=pre[i]) 
		for (int v=to[i],tmp,j=x[u];j>=0;j--) 
		{
			tmp=inf;
			if (j>=x[v]) tmp=min(tmp,dp[j-x[v]]+y[v]);
			if (j>=y[v]) tmp=min(tmp,dp[j-y[v]]+x[v]);
			dp[j]=tmp;
		}
	y[u]=inf;
	for (int i=0;i<=x[u];i++) y[u]=min(y[u],dp[i]);
	if (y[u]>=inf) 
	{
		//printf("-%d\n",u);
		o=true;
	}
}

int main()
{
	scanf("%d",&n);
	for (int p,i=2;i<=n;i++) 
	{
		scanf("%d",&p);
		addedge(p,i);
	}
	for (int i=1;i<=n;i++) scanf("%d",&x[i]);
	dfs(1);
	if (o) printf("IMPOSSIBLE");else printf("POSSIBLE");
	return 0;
}
