A. Nauuo and Cardstime limit per test1.5 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputNauuo is a girl who loves playing cards.One day she was playing cards but found that the cards were mixed with some empty ones.There are n cards numbered from 1 to n, and they were mixed with another n empty cards. She piled up the 2n cards and drew n of them. The n cards in Nauuo's hands are given. The remaining n cards in the pile are also given in the order from top to bottom.In one operation she can choose a card in her hands and play it — put it at the bottom of the pile, then draw the top card from the pile.Nauuo wants to make the n numbered cards piled up in increasing order (the i-th card in the pile from top to bottom is the card i) as quickly as possible. Can you tell her the minimum number of operations?InputThe first line contains a single integer n (1\le n\le 2\cdot 10^5) — the number of numbered cards.The second line contains n integers a_1,a_2,\ldots,a_n (0\le a_i\le n) — the initial cards in Nauuo's hands. 0 represents an empty card.The third line contains n integers b_1,b_2,\ldots,b_n (0\le b_i\le n) — the initial cards in the pile, given in order from top to bottom. 0 represents an empty card.It is guaranteed that each number from 1 to n appears exactly once, either in a_{1..n} or b_{1..n}.OutputThe output contains a single integer — the minimum number of operations to make the n numbered cards piled up in increasing order.ExamplesInput
3
0 2 0
3 0 1
Output
2Input
3
0 2 0
1 0 3
Output
4Input
11
0 0 0 5 0 0 0 4 0 0 11
9 2 6 0 8 1 7 0 3 0 10
Output
18NoteExample 1We can play the card 2 and draw the card 3 in the first operation. After that, we have [0,3,0] in hands and the cards in the pile are [0,1,2] from top to bottom.Then, we play the card 3 in the second operation. The cards in the pile are [1,2,3], in which the cards are piled up in increasing order.Example 2Play an empty card and draw the card 1, then play 1, 2, 3 in order.
3
0 2 0
3 0 1

2
['greedy', 'implementation', '*1800']