#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>using namespace std;#define LL long long#define lson l, mid, rt << 1#define rson mid + 1, r, rt << 1 | 1#define CY 50010LL mi[CY << 2], cos[CY], val[CY];int n;void Up(LL &rt, LL &ls, LL &rs) {rt = min(ls, rs);}void update(int pos, LL v, int l, int r, int rt) {if (l == r) mi[rt] = v;else {int mid = (l + r) >> 1;if (pos <= mid) update(pos, v, lson);else update(pos, v, rson);Up(mi[rt], mi[rt << 1], mi[rt << 1 | 1]);}} LL query(int L, int R, int l, int r, int rt) {if (L == l && R == r) return mi[rt];int mid = (l + r) >> 1;if (R <= mid) return query(L, R, lson);else if (L > mid) return query(L, R, rson);else return min(query(L, mid, lson), query(mid + 1, R, rson));}void input() {for (int i = 1; i <= n; ++i) scanf("%lld", &cos[i]);for (int i = 1; i <= n; ++i) scanf("%lld", &val[i]);}void solve() {LL ret;for (int i = n; i >= 1; --i) {if ((LL)i + val[i] >= (LL)n + 1) ret = cos[i];else ret = query(i + 1, i + val[i], 1, n, 1) + cos[i];update(i, ret, 1, n, 1);}printf("%lldn", query(1, 1, 1, n, 1)); }int main() {while (1 == scanf("%d", &n)) {input();solve();}return 0;}
