#include <bits/stdc++.h> using ll = std::int64_t; int main(){ std::cin.tie(nullptr); std::ios::sync_with_stdio(false); int N; std::cin >> N; std::vector<ll> A(N), B(N), C(N); for(int i=0;i<N;i++){ std::cin >> A[i]; } for(int i=0;i<N;i++){ std::cin >> B[i]; } for(int i=0;i<N;i++){ std::cin >> C[i]; } auto trans = [](int j, int k){ return j % 3 <= k % 3 && j / 3 <= k / 3; }; std::vector dp(N + 1, std::vector<ll>(9, 0)); dp[0][0] = 0; for(int i=0;i<N;i++){ for(int j=0;j<9;j++){ for(int k=0;k<9;k++){ if(!trans(j, k)){continue;} ll v = 0; if(k % 3 == 1 && k / 3 == 1){ v += C[i]; }else if(k % 3 == 1 || k / 3 == 1){ v += B[i]; }else{ v += A[i]; } dp[i + 1][k] = std::max(dp[i + 1][k], dp[i][j] + v); } } } ll res = *std::max_element(std::begin(dp[N]), std::end(dp[N])); std::cout << res << std::endl; }