#include <iostream>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>	// require sort next_permutation count __gcd reverse etc.
#include <cstdlib>	// require abs exit atof atoi 
#include <cstdio>		// require scanf printf
#include <functional>
#include <numeric>	// require accumulate
#include <cmath>		// require fabs
#include <climits>
#include <limits>
#include <cfloat>
#include <iomanip>	// require setw
#include <sstream>	// require stringstream 
#include <cstring>	// require memset
#include <cctype>		// require tolower, toupper
#include <fstream>	// require freopen
#include <ctime>		// require srand
#define rep(i,n) for(int i=0;i<(n);i++)
#define ALL(A) A.begin(), A.end()

/*
	No.9 モンスターのレベル上げ

	優先度付きキュー
*/

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

int main()
{
	ios_base::sync_with_stdio(0);
	int N; cin >> N;
	vector<int> A(N, 0 );
	rep (i, N ) cin >> A[i];
	vector<int> B(N, 0 );
	rep (i, N ) cin >> B[i];

	int res = 0;
	rep (i, N ){
		priority_queue <int, vector<int>, greater<int> > que;
		rep (j, N )
			que.push (A[j]*10000 ); 

		int start = i;
		for (int j = 0, k = start; j < N; j++, k = (k + 1 ) % N ){
			int curr = que.top(); que.pop();
			que.push (curr + B[k]/2 * 10000 + 1 );
		} // end for

		int now = 0;
		while (!que.empty() ){
			int curr = que.top(); que.pop();
			now = max (now, curr%10000 );
		} // end while

		res = max (res, now );
	} // end rep

	cout << res << endl;

	return 0;
}