#include <bits/stdc++.h>
#define inf 0x3f3f
using namespace std;
const int maxn=1e3+10;
int f[maxn],n,dp[2][maxn*5],x[maxn];
vector<int>g[maxn];

void dfs(int u){
    for (auto v:g[u]) dfs(v);
    memset(dp[0],inf,sizeof(dp[0]));
    int cur=0;
    dp[cur][0]=0;
    for (auto v:g[u]){
        cur^=1;
        memset(dp[cur],inf,sizeof(dp[cur]));
        for (int j=0; j<=x[u]; j++){
            if(j-x[v]>=0) dp[cur][j]=min(dp[cur][j],dp[cur^1][j-x[v]]+f[v]);
            if(j-f[v]>=0) dp[cur][j]=min(dp[cur][j],dp[cur^1][j-f[v]]+x[v]);
        }
    }
    for (int i=0; i<=x[u]; i++) f[u]=min(f[u],dp[cur][i]);
}

int main(){
    scanf("%d",&n);
    for (int p,i=2; i<=n; i++) {
        scanf("%d",&p);
        g[p].push_back(i);
    }
    for (int i=1; i<=n; i++) scanf("%d",&x[i]);
    memset(f,inf,sizeof(f));
    dfs(1);
//    for (int i=1; i<=n; i++) printf("%d ",f[i]);
//    printf("\n");
    if(f[1]<0x3f3f3f) puts("POSSIBLE");
    else puts("IMPOSSIBLE");
    return 0;
}
