P4724 [CF1028H] Make Square
NOI
题目描述

We call an array $b_1, b_2, \ldots, b_m$ good, if there exist two indices $i < j$ such that $b_i \cdot b_j$ is a perfect square.

Given an array $b_1, b_2, \ldots, b_m$, in one action you can perform one of the following:

  • multiply any element $b_i$ by any prime $p$;
  • divide any element $b_i$ by prime $p$, if $b_i$ is divisible by $p$.

Let $f(b_1, b_2, \ldots, b_m)$ be the minimum number of actions needed to make the array $b$ good.

You are given an array of $n$ integers $a_1, a_2, \ldots, a_n$ and $q$ queries of the form $l_i, r_i$. For each query output $f(a_{l_i}, a_{l_i + 1}, \ldots, a_{r_i})$.

Input

The first line contains two integers $n$ and $q$ ($2 \le n \le 194\,598$, $1 \le q \le 1\,049\,658$) — the length of the array and the number of queries.

The second line contains $n$ integers $a_1, a_2, \ldots, a_n$ ($1 \le a_i \le 5\,032\,107$) — the elements of the array.

Each of the next $q$ lines contains two integers $l_i$ and $r_i$ ($1 \le l_i < r_i \le n$) — the parameters of a query.

Output

Output $q$ lines — the answers for each query in the order they are given in the input.

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
10 10 34 37 28 16 44 36 43 50 22 13 1 3 4 8 6 10 9 10 3 10 8 9 5 6 1 4 1 7 2 6
样例输出
2 0 1 3 0 1 1 1 0 0
提示

In the first query of the first sample you can multiply second number by 7 to get 259 and multiply the third one by 37 to get 1036. Then $a_2 \cdot a_3 = 268\,324 = 518^2$.

In the second query subarray is already good because $a_4 \cdot a_6 = 24^2$.

In the third query you can divide 50 by 2 to get 25. Then $a_6 \cdot a_8 = 30^2$.