codeforces#P1575G. GCD Festival

GCD Festival

Description

Mr. Chanek has an array $a$ of $n$ integers. The prettiness value of $a$ is denoted as:

$$\sum_{i=1}^{n} {\sum_{j=1}^{n} {\gcd(a_i, a_j) \cdot \gcd(i, j)}}$$

where $\gcd(x, y)$ denotes the greatest common divisor (GCD) of integers $x$ and $y$.

In other words, the prettiness value of an array $a$ is the total sum of $\gcd(a_i, a_j) \cdot \gcd(i, j)$ for all pairs $(i, j)$.

Help Mr. Chanek find the prettiness value of $a$, and output the result modulo $10^9 + 7$!

The first line contains an integer $n$ ($2 \leq n \leq 10^5$).

The second line contains $n$ integers $a_1, a_2, \ldots, a_n$ ($1 \leq a_i \leq 10^5$).

Output an integer denoting the prettiness value of $a$ modulo $10^9 + 7$.

Input

The first line contains an integer $n$ ($2 \leq n \leq 10^5$).

The second line contains $n$ integers $a_1, a_2, \ldots, a_n$ ($1 \leq a_i \leq 10^5$).

Output

Output an integer denoting the prettiness value of $a$ modulo $10^9 + 7$.

Samples

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3 6 2 1 4
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