#include <bits/stdc++.h>
using namespace std;
const int N=1e3+10,X=5e3+10;
int n,p,ans=0,top[N],xx[N],f[2][X],sum[X];
struct lol {int x,y;} e[N];
void freo(){
	freopen(".in","r",stdin);
	freopen(".out","w",stdout);
}
void ein(int x,int y){
	e[++ans]=(lol){top[x],y};
	top[x]=ans;
}
void init(){
	scanf("%d",&n);
	for(int i=1;++i<=n;scanf("%d",&p),ein(p,i));
	for(int i=0;++i<=n;scanf("%d",&xx[i]));
}
void dfs(int x){
	for(int i=top[x],y;i;y=e[i].y,dfs(y),i=e[i].x);
	int cnt=0;
	memset(f[0],0x3f,sizeof(f[0]));
	f[0][0]=0;
	for(int i=top[x],y;i;i=e[i].x){
		y=e[i].y;
		cnt^=1;
		memset(f[cnt],0x3f,sizeof(f[cnt]));
		for(int j=-1;++j<=xx[x];
			j<xx[y]?:f[cnt][j]=min(f[cnt][j],f[cnt^1][j-xx[y]]+sum[y]),
			j<sum[y]?:f[cnt][j]=min(f[cnt][j],f[cnt^1][j-sum[y]]+xx[y]));
	}
	for(int i=-1;++i<=xx[x];sum[x]=min(sum[x],f[cnt][i]));
}
void work(){
	memset(sum,0x3f,sizeof(sum));
	dfs(1);
}
void prin(){
	printf(sum[1]==0x3f3f3f3f?"IMPOSSIBLE":"POSSIBLE");
}
int main(){
//	freo();
	init();
	work();
	prin();
	return 0;
}
