#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <vector>
using namespace std;
typedef long long LL;
const LL INF = 0x3f3f3f3f3f3f3f3f;

vector <LL> G[1005];
LL w[1005],z[1005],dp[5005];
LL n,ff;

void dfs(LL u,LL f){
	for(LL i = 0;i < G[u].size();i ++) dfs(G[u][i],u);
	
	for(LL j = 0;j <= w[u];j ++) dp[j] = INF; dp[0] = 0;
	for(LL i = 0;i < G[u].size();i ++){
		LL v = G[u][i];
		for(LL j = w[u];j >= 0;j --){
			LL mi = INF;
			if(j >= w[v]) mi = min(mi,dp[j - w[v]] + z[v]);
			if(j >= z[v]) mi = min(mi,dp[j - z[v]] + w[v]);
			dp[j] = mi;
		}
	}
	for(LL i = w[u];i >= 0;i --) z[u] = min(z[u],dp[i]);
}

int main(){
	memset(z,INF,sizeof(z));
	cin >> n;
	for(LL i = 2;i <= n;i ++){
		cin >> ff;
		G[ff].push_back(i);
	}
	for(LL i = 1;i <= n;i ++) cin >> w[i];
	dfs(1,0);
	cout << (z[1] < INF ? "POSSIBLE" : "IMPOSSIBLE") << endl;
	return 0;
}