题目描述
Problem Statement
Given is $a permutation P=(P_1,P_2,\ldots,P_N)$ of the integers from 1 through N.
Find the number of pairs of integers (i,j) such that $1\leq i\leq j\leq N satisfying GCD(i,j)\neq 1$ and $GCD(P_i,P_j)\neq 1$.
Here, for positive integers x and y, GCD(x,y) denotes the greatest common divisor of x and y.
Input
Input is given from Standard Input in the following format:
N
$P_1 P_2 \ldots P_N$
Output
Print the answer.
Constraints
- $1 \leq N \leq 2\times 10^5$
- $(P_1,P_2,\ldots,P_N)$ is a permutation of $(1,2,\ldots,N)$.
- All values in input are integers.
Sample Input 1
6
5 1 3 2 4 6
Sample Output 1
6
Six pairs (3,3), (3,6), (4,4), (4,6), (5,5), (6,6) satisfy the condition, so 6 should be printed.
Sample Input 2
12
1 2 3 4 5 6 7 8 9 10 11 12
Sample Output 2
32
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
6
5 1 3 2 4 6
样例输出
6