#include <bits/stdc++.h>
using namespace std;

#ifdef DEBUG
#define fast
#else
#define fast cin.tie(0)->sync_with_stdio(0)
#define cerr if(1);else cerr
#define endl '\n'
#endif
#define _ <<' '<<
#define ALL(v) v.begin(),v.end()
#define ft first
#define sd second

using ll = long long;
using ld = long double;
using pii = pair<int,int>;

constexpr int MAXN = 1000;
constexpr int MAXB = 10;
constexpr int MAXT = MAXB * MAXN;

void chmax(auto& a, auto b) {
    if (a < b) a = b;
}

signed main() {
    fast;

    int n;
    cin >> n;
    vector<int> A(n), B(n);
    for (auto &x: A) cin >> x;
    for (auto &x: B) cin >> x;

    int T = accumulate(ALL(B), 0);
    vector<int> dp(T*2+1, -1);
    for (int i = 0; i < n; i++) {
        for (int t = T; t >= 0; t--)
            if (dp[t] == i-1 or dp[t] == i-2)
                chmax(dp[t+B[i]], i);
    }

    for (int t = T; t > 0; t--)
        if (dp[t-1] == dp[t]-2) {
            int i = dp[t];
            for (int j = 1; j < B[i] and t-j >= 0; j++)
                chmax(dp[t-j], i-1);
        }

    for (int t = 0; t <= T; t++)
        cerr << setw(2) << 1+t << " \n"[t==T];
    for (int t = 0; t <= T; t++)
        cerr << setw(2) << 1+dp[t] << " \n"[t==T];

    int time = 0;
    for (int i = 0; i < n; i++) {
        while (time < T and dp[time] < i)
            time++;
        cerr _ i+1 _ A[i] _ time+1 _ endl;
        time += A[i];
    }
    cout << time << endl;


    return 0;
}