#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll, ll>;
#define rep(i, a, b) for(ll i = a; i < b; ++i)
#define rrep(i, a, b) for(ll i = a; i >= b; --i)
constexpr ll inf = 4e18;
struct SetupIO {
    SetupIO() {
        ios::sync_with_stdio(0);
        cin.tie(0);
        cout << fixed << setprecision(30);
    }
} setup_io;
int main(void) {
    ll n;
    cin >> n;
    vector<vector<ll>> a(3, vector<ll>(n));
    rep(i, 0, 3) {
        rep(j, 0, n) {
            cin >> a[i][j];
        }
    }
    vector<vector<vector<ll>>> dp(n + 1, vector<vector<ll>>(3, vector<ll>(3, -inf)));
    dp[0][0][0] = 0;
    rep(i, 0, n) {
        rep(j, 0, 3) {
            rep(k, 0, j + 1) {
                rep(j1, 0, j + 1) {
                    rep(k1, 0, min(k, j1) + 1) {
                        dp[i + 1][j][k] = max(dp[i + 1][j][k], dp[i][j1][k1] + a[int(j == 1) + int(k == 1)][i]);
                    }
                }
            }
        }
    }
    ll ans = 0;
    rep(i, 0, 3) {
        rep(j, 0, 3) {
            ans = max(ans, dp[n][i][j]);
        }
    }
    cout << ans << '\n';
}