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

#define rep(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
#define rrep(i, s, n) for (int i = (int)(n)-1; i >= (int)(s); i--)

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	int n; cin >> n;
	vector a(3, vector<ll>(n));
	rep(j,0,3) rep(i,0,n) cin >> a[j][i];

	// index, used(0-2), now? 
	vector dp(n+1, vector(3, vector<ll>(3,-1e18)));
	dp[0][0][0] = 0;
	
	rep(i,0,n){
		rep(j,0,3){
			rep(x,0,3-j){
				rep(k,0,3){
					rep(y,0,k+1){
						if (dp[i][j][k] < 0) continue;
						dp[i+1][j+x][y+x] = max(dp[i+1][j+x][y+x], dp[i][j][k] + a[y+x][i]);
					}
				}
			}
		}
	}
	
	ll ans = -1e18;
	rep(i,0,3){
		rep(j,0,3){
			ans = max(ans, dp[n][i][j]);
		}
	}
	cout << ans << '\n';
}