Codeforces Round 198 (Div. 1)
A
Tourist Problem
Codeforces
未评级
原题
←B →
翻译中…

Iahub is a big fan of tourists. He wants to become a tourist himself, so he planned a trip. There are $*n*$ destinations on a straight road that Iahub wants to visit. Iahub starts the excursion from kilometer 0. The $*n*$ destinations are described by a non-negative integers sequence $*a*_{1}$, $*a*_{2}$, ..., $*a*_{*n*}$. The number $*a*_{*k*}$ represents that the $*k*$th destination is at distance $*a*_{*k*}$ kilometers from the starting point. No two destinations are located in the same place.

翻译中…

Iahub wants to visit each destination only once. Note that, crossing through a destination is not considered visiting, unless Iahub explicitly wants to visit it at that point. Also, after Iahub visits his last destination, he doesn't come back to kilometer 0, as he stops his trip at the last destination.

翻译中…

The distance between destination located at kilometer $*x*$ and next destination, located at kilometer $*y*$, is $|*x* - *y*|$ kilometers. We call a "route" an order of visiting the destinations. Iahub can visit destinations in any order he wants, as long as he visits all $*n*$ destinations and he doesn't visit a destination more than once.

翻译中…

Iahub starts writing out on a paper all possible routes and for each of them, he notes the total distance he would walk. He's interested in the average number of kilometers he would walk by choosing a route. As he got bored of writing out all the routes, he asks you to help him.

翻译中…

Input

翻译中…

The first line contains integer $*n*$ ($2 ≤ *n* ≤ 10^{5}$). Next line contains $*n*$ distinct integers $*a*_{1}$, $*a*_{2}$, ..., $*a*_{*n*}$ ($1 ≤ *a*_{*i*} ≤ 10^{7}$).

翻译中…

Output

翻译中…

Output two integers — the numerator and denominator of a fraction which is equal to the wanted average number. The fraction must be irreducible.

翻译中…

Note

翻译中…

Consider 6 possible routes:

翻译中…
  • [2, 3, 5]: total distance traveled: |2 – 0| + |3 – 2| + |5 – 3| = 5;
  • [2, 5, 3]: |2 – 0| + |5 – 2| + |3 – 5| = 7;
  • [3, 2, 5]: |3 – 0| + |2 – 3| + |5 – 2| = 7;
  • [3, 5, 2]: |3 – 0| + |5 – 3| + |2 – 5| = 8;
  • [5, 2, 3]: |5 – 0| + |2 – 5| + |3 – 2| = 9;
  • [5, 3, 2]: |5 – 0| + |3 – 5| + |2 – 3| = 8.
翻译中…

The average travel distance is image = image = image.

翻译中…

样例

Input #1
3
2 3 5
Output #1
22 3
InputCopy OutputCopy
题目信息
题号
341A
时间限制
1 s
内存限制
256 MB

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