#include<cstdio>
#include<cstring>
#include<algorithm>
#define f(x) memset(x,0x3f,sizeof(x))
using namespace std;
const int mxn=1024;
int T,n,m,ax[mxn],head[mxn],f[mxn],a[mxn],b[mxn],g[mxn][8192];
struct ed{int to,nxt;}edge[mxn<<1];
void addedge(int u,int v){edge[++m]=(ed){v,head[u]},head[u]=m;}
#define rep for (int i=head[u],v;i;i=edge[i].nxt) if ((v=edge[i].to)!=fa)
void dfs(int u,int fa){
	rep dfs(v,u); f(g[1]),m=g[1][0]=0; rep a[++m]=f[v],b[m]=ax[v];
	for (int i=1;i<=m&&(f(g[i+1]),1);++i)
		for (int j=0;j<=ax[u];++j){
			if (j+a[i]<=ax[u]) g[i+1][j+a[i]]=min(g[i+1][j+a[i]],g[i][j]+b[i]);
			if (j+b[i]<=ax[u]) g[i+1][j+b[i]]=min(g[i+1][j+b[i]],g[i][j]+a[i]);
		}
	for (int i=ax[u];i>=0;--i) f[u]=min(f[u],g[m+1][i]);
}
int main()
{
	for (int i=(scanf("%d",&n),f(f),2),x;i<=n;++i) scanf("%d",&x),addedge(i,x),addedge(x,i);
	for (int i=1;i<=n;++i) scanf("%d",&ax[i]);
	return dfs(1,0),puts(f[1]<0x3f3f3f3f?"POSSIBLE":"IMPOSSIBLE"),0;
}