# Reverse Roman Numerals

Simple

In this CheckiO mission Roman Numerals you have to convert a decimal number into its representation as a Roman number.
Here you have to do the same but the other way around.

You are given a Roman number as a string and your job is to convert this number into its decimal representation.

A valid Roman number, in the context of this mission, will only contain Roman numerals as per the below table and follow the rules of the subtractive notation.
Check out this Wikipedia article for more details on how to form Roman numerals.

NumeralValue
I1 (unus)
V5 (quinque)
X10 (decem)
L50 (quinquaginta)
C100 (centum)
D500 (quingenti)
M1,000 (mille)

Input: A Roman number as a string.

Output: The decimal representation of the Roman number as an int.

Example:

```reverse_roman('VI') == 6
reverse_roman('LXXVI') == 76
reverse_roman('CDXCIX') == 499
reverse_roman('MMMDCCCLXXXVIII') == 3888```

Precondition:
len(roman_string) > 0
all(char in "MDCLXVI" for char in roman_string) == True
0 < reverse_roman(roman_string) < 4000

49
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CheckiO Extensions allow you to use local files to solve missions. More info in a blog post.

In order to install CheckiO client you'll need installed Python (version at least 3.8)

Install CheckiO Client first:

`pip3 install checkio_client`

`checkio --domain=py config --key=`

Sync solutions into your local folder

`checkio sync`

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`checkio serv -d`

Alternatevly, you can install Chrome extension or FF addon

`checkio install-plugin`
`checkio install-plugin --ff`
`checkio install-plugin --chromium`

Read more here about other functionality that the checkio client provides. Feel free to submit an issue in case of any difficulties.

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