#include<bits/stdc++.h>

using namespace std;

const int N = 1e4 + 10;
int f[N],dp[N],x[N];
vector<int>edge[N];
void dfs(int u)
{
    for(int i = 0;i < edge[u].size();i++)
        dfs(edge[u][i]);
    memset(dp,0x3f,sizeof(dp));
    dp[0] = 0;
    for(int i = 0;i < edge[u].size();i++)
    {
        int v = edge[u][i];
        for(int j = x[u];j >= 0;j--)
        {
            int inf = 0x3f3f3f3f;
            if(j - f[v] >= 0)   inf = min(inf,dp[j - f[v]] + x[v]);
            if(j - x[v] >= 0)   inf = min(inf,dp[j - x[v]] + f[v]);
            dp[j] = inf;
        }
    }
    for(int i = 0;i <= x[u];i++)
        f[u] = min(f[u],dp[i]);
}
int main()
{
    int n,pre;
    scanf("%d",&n);
    for(int i = 2;i <= n;i++)
        scanf("%d",&pre),edge[pre].push_back(i);
    for(int i = 1;i <= n;i++)
        scanf("%d",x+i);
    memset(f,0x3f,sizeof(f));
    dfs(1);
    if(f[1] >= 0x3f3f3f3f)
        puts("IMPOSSIBLE");
    else
        puts("POSSIBLE");
    return 0;
}
