#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 200010;
int n;
int a[N], b[N];
ll ans, pre;

int main() {
	ios::sync_with_stdio(0); cin.tie(nullptr);
	cin >> n;
	for(int i = 1; i <= n; i++) cin >> b[i];
	for(int i = 1; i <= n; i++) cin >> a[i];
	int cnt = 0;
	ans = max(a[n], b[n]) * 2;
	for(int i = 1, j = 1; i <= n || j <= n;) {
		if(j > n || (i <= n && a[i] <= b[j])) {
			++cnt;
			if(cnt == 0) {
				pre += a[i] * 2;
			}
			++i;
		}
		else {
			--cnt;
			if(cnt == -1) {
				ans = min(ans, pre + max(a[n], b[n]) * 2 - b[j]);
				pre -= 2 * b[j];
			}
			++j;
		}
	}
	ans = min(ans, pre + max(a[n], b[n]));
	cout << ans << "\n";
	return 0;
}