题目描述

Two arrays u and v each with m distinct elements are called equivalent if and only if $\mathrm{RMQ}(u, l, r) = \mathrm{RMQ}(v, l, r)$ for all $1 \leq l \leq r \leq m$ where $\mathrm{RMQ}(w, l, r)$ denotes the index of the minimum element among $w_l, w_{l + 1}, \dots, w_{r}​.$ Since the array contains distinct elements, the definition of minimum is unambiguous.

Bobo has two arrays a and b each with n distinct elements. Find the maximum number $p \leq n$ where $\{a_1, a_2, \dots, a_p\}$ and $\{b_1, b_2, \dots, b_p\}$ are equivalent.

输入格式

The input consists of several test cases and is terminated by end-of-file. The first line of each test case contains an integer n. The second line contains n integers $a_1, a_2, \dots, a_n$. The third line contains n integers $b_1, b_2, \dots, b_n$.

• $1 \leq n \leq 10^5$
• $1 \leq a_i, b_i \leq n$
• $\{a_1, a_2, \dots, a_n\}$ are distinct.
• $\{b_1, b_2, \dots, b_n\}$ are distinct.
• The sum of n does not exceed $5 \times 10^5$.

输出格式

For each test case, print an integer which denotes the result.

样例

样例输入

2
1 2
2 1
3
2 1 3
3 1 2
5
3 1 5 2 4
5 2 4 3 1

样例输出

1
3
4