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

typedef long long ll;
const double EPS = 1e-9;
typedef vector<ll> vecl;
typedef pair<ll, ll> pairl;
#define ALL(v) v.begin(), v.end()
#define REP(i, x, n) for(int i = x; i < n; i++)
#define rep(i, n) REP(i, 0, n)
template<class T, class C> void chmax(T& a, C b){ a>b?:a=b; }
template<class T, class C> void chmin(T& a, C b){ a<b?:a=b; }

#define MOD097 1000000007
#define INF 1<<18;

///// For Debug

#define repi(itr, ds) for (auto itr = ds.begin(); itr != ds.end(); itr++)
// vector
template <typename T>
istream &operator>>(istream &is, vector<T> &vec) {
    for (T &x : vec) is >> x;
    return is;
}
// pair
template <typename T, typename U>
ostream &operator<<(ostream &os, pair<T, U> &pair_var) {
    os << "(" << pair_var.first << ", " << pair_var.second << ")";
    return os;
}
// vector
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &vec) {
    os << "{";
    for (int i = 0; i < vec.size(); i++) {
        os << vec[i] << (i + 1 == vec.size() ? "" : ", ");
    }
    os << "}";
    return os;
}
// map
template <typename T, typename U>
ostream &operator<<(ostream &os, map<T, U> &map_var) {
    os << "{";
    repi(itr, map_var) {
        os << *itr;
        itr++;
        if (itr != map_var.end()) os << ", ";
        itr--;
    }
    os << "}";
    return os;
}
// set
template <typename T>
ostream &operator<<(ostream &os, set<T> &set_var) {
    os << "{";
    repi(itr, set_var) {
        os << *itr;
        itr++;
        if (itr != set_var.end()) os << ", ";
        itr--;
    }
    os << "}";
    return os;
}
 
#define DUMPOUT cerr
 
void dump_func() {
    DUMPOUT << endl;
}
template <class Head, class... Tail>
void dump_func(Head &&head, Tail &&... tail) {
    DUMPOUT << head;
    if (sizeof...(Tail) > 0) {
        DUMPOUT << ", ";
    }
    dump_func(std::move(tail)...);
}

// 提出時はコメントアウト
// #define LOCAL
#define DEBUG_

#ifndef LOCAL
#undef DEBUG_
#endif

#ifdef DEBUG_

#define DEB
#define dump(...)                                                              \
    DUMPOUT << "  " << string(#__VA_ARGS__) << ": "                            \
            << "[" << to_string(__LINE__) << ":" << __FUNCTION__ << "]"        \
            << endl                                                            \
            << "    ",                                                         \
        dump_func(__VA_ARGS__)
#else
#define DEB if (false)
#define dump(...)

#endif

//////////

ll N;

ll pos(ll i,ll j) {
    return i * N + j;
}

int main() {
    #ifdef LOCAL
    ifstream in("../../Atcoder/input.txt");
    cin.rdbuf(in.rdbuf());
    #endif


    cin >> N;

    vector<vector<ll>> A(2,vector<ll>(N));
    rep(i,2) {
        rep(j,N) {
             cin >> A[i][j];
        }
    }

    ll dp[2*N][2*N];

    rep(i,2*N) {
        rep(j,2*N) {
            dp[i][j] = -INF;
        }
        dp[i][i] = 0;
    }

    rep(i,2)  {
        rep(j,N) {
            ll x = pos(i,j);
            ll di[2] = {0,1};
            ll dj[2] = {1,0};

            rep(k,2) {
                int ni = i+di[k];
                int nj = j+dj[k]; 
                if (ni<2 && nj<N) {
                    dp[x][pos(ni,nj)] = A[ni][nj];
                }
            }
        }
    }

    dp[0][0] = A[0][0];

    rep(k,2*N) {
        rep(i,2*N){
            rep(j,2*N) {
                dp[i][j] = max(dp[i][j],dp[i][k] + dp[k][j]);
            }
        }
    }

    cout << dp[0][2*N-1] - A[0][0] << endl;
       

    return 0;
}


Measured memory_bytes: 3832