#include <cstdio>
#include <vector>
using namespace std;
const int MAXN = 1005;
const int inf = 1e9;
vector<int> adj[MAXN];
int n, x[MAXN];
int f[MAXN][2];
int g[MAXN][MAXN * 5];
void dfs(int u) {
    for(int i = 0; i < adj[u].size(); i++) dfs(adj[u][i]);
    for(int k = 0; k < 2; k++) {
        for(int i = 1; i <= adj[u].size(); i++) {
            int v = adj[u][i - 1];
            for(int j = 0; j <= x[u]; j++) {
                g[i][j] = inf;
                if(x[v] <= j) g[i][j] = std::min(g[i][j], g[i - 1][j - x[v]] + f[v][k]);
                if(f[v][k ^ 1] <= j) g[i][j] = std::min(g[i][j], g[i - 1][j - f[v][k ^ 1]] + x[v]);
            }
        }
        f[u][k] = g[adj[u].size()][x[u]];
    }
}
int main() {
    scanf("%d", &n);
    for(int i = 2; i <= n; i++) {
        int p; scanf("%d", &p);
        adj[p].push_back(i);
    }
    for(int i = 1; i <= n; i++) scanf("%d", &x[i]);
    dfs(1);
    if(f[1][0] < inf || f[1][1] < inf) printf("POSSIBLE\n");
    else printf("IMPOSSIBLE\n");
    return 0;
}