---
category_name: hard
problem_code: SEAARC
problem_name: 'Sereja and Arcs'
languages_supported:
- ADA
- ASM
- BASH
- BF
- C
- 'C99 strict'
- CAML
- CLOJ
- CLPS
- 'CPP 4.3.2'
- 'CPP 4.9.2'
- CPP14
- CS2
- D
- ERL
- FORT
- FS
- GO
- HASK
- ICK
- ICON
- JAVA
- JS
- 'LISP clisp'
- 'LISP sbcl'
- LUA
- NEM
- NICE
- NODEJS
- 'PAS fpc'
- 'PAS gpc'
- PERL
- PERL6
- PHP
- PIKE
- PRLG
- PYTH
- 'PYTH 3.4'
- RUBY
- SCALA
- 'SCM guile'
- 'SCM qobi'
- ST
- TCL
- TEXT
- WSPC
max_timelimit: '5'
source_sizelimit: '50000'
problem_author: sereja
problem_tester: shiplu
date_added: 19-03-2014
tags:
- combinatorics
- hard
- june14
- sereja
editorial_url: 'http://discuss.codechef.com/problems/SEAARC'
time:
view_start_date: 1402911000
submit_start_date: 1402911000
visible_start_date: 1402911000
end_date: 1735669800
current: 1493556988
layout: problem
---
All submissions for this problem are available.### Read problems statements in [Mandarin Chinese](http://www.codechef.com/download/translated/JUNE14/mandarin/SEAARC1.pdf) and [Russian](http://www.codechef.com/download/translated/JUNE14/russian/SEAARC1.pdf).
Sereja have **N** points, with coordinates **(1, 0), (2, 0), ..., (N, 0)**. Every point has a color, point with coordinate **(i, 0)** has color **A\[i\]**.
Sereja have painted arcs between every pair of points with same color. Formally Sereja painted arc between points **(i, 0)** and **(j, 0)** if **A\[i\] = A\[j\]** and **i != j**, such arc has color **A\[i\]**. All the arcs are painted such way that they will reside along the positive quadrant.
Now Sereja wants to know how many pairs of arc with different color intersect?
### Input
First line contain integer **N**. Next line contain integers **A\[1\], A\[2\], ..., A\[N\]**.
### Output
In single line output answer modulo **1000000007 (10^9 + 7)**.
### Constraints
- **1** ≤ **N** ≤ **100000**
- **1** ≤ **A\[i\]** ≤ **100000**
### Example
<pre><b>Input:</b>
4
1 2 1 2
<b>Output:</b>
1
</pre>