#include <cstdio>
#include <algorithm>
using namespace std;
pair<int, int> w[500010];
int n, a[500010];
int fa[500010], siz[500010];
long long ans[500010], sum[500010];
int find(int x) {
    if (x == fa[x]) return x;
    return fa[x] = find(fa[x]);
}
void merge(int x, int y) {
    int fx = find(x), fy = find(y);
    if (fx != fy) {
        fa[fx] = fy;
        ans[fy] = ans[fx] + ans[fy] + siz[fy] * sum[fx];
        siz[fy] += siz[fx];
        sum[fy] += sum[fx];
    }
}
int main() {
    scanf("%d", &n);
    for (int i = 1; i <= n; i++) {
        scanf("%d", &a[i]);
    }
    for (int i = 1; i <= n; i++) {
        scanf("%d", &w[i].first);
        w[i].second = i;
        fa[i] = i;
        siz[i] = 1;
        sum[i] = w[i].first;
        ans[i] = w[i].first;
    }
    sort(w + 1, w + n + 1);
    for (int i = 1; i <= n; i++) {
        merge(w[i].second, a[w[i].second]);
    }
    if (siz[0] != n) ans[0] = -1;
    printf("%d\n", ans[0]);
    return 0;
}