##### Canadian Computing Competition: 2012 Stage 1, Senior #2

This question involves calculating the value of *aromatic* numbers which are a combination of Arabic digits and Roman numerals.

An aromatic number is of the form , where each is an Arabic digit, and each is a Roman numeral. Each pair contributes a value described below, and by adding or subtracting these values together we get the value of the entire aromatic number.

An Arabic digit can be 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9. A Roman numeral is one of the seven letters I, V, X, L, C, D, or M. Each Roman numeral has a base value:

Symbol | I | V | X | L | C | D | M |
---|---|---|---|---|---|---|---|

Base value | 1 | 5 | 10 | 50 | 100 | 500 | 1000 |

The value of a pair is times the base value of . Normally, you add up the values of the pairs to get the overall value. However, wherever there are consecutive symbols with having a *strictly bigger* base value than , the value of pair must be *subtracted* from the total, instead of being *added*.

For example, the number has the value and has the value .

Write a program that computes the values of aromatic numbers.

#### Input Specification

The input is a valid aromatic number consisting of between and symbols.

#### Output Specification

The output is the decimal value of the given aromatic number.

#### Sample Input 1

`3M1D2C`

#### Output for Sample Input 1

`3700`

#### Sample Input 2

`2I3I2X9V1X`

#### Output for Sample Input 2

`-16`

## Comments

Can dmoj not speak english?

confusion noisesNote: From the example 3X2I4X, because 2I(AR)'s base is smaller than 4X(A′R′), so 2I(AR) should be subtracted from the total(-2 * I = -2 * 1)

Should the statement be "the value of pair AR must be subtracted from the total" instead of "the value of pair A′ must be subtracted from the total"?

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I don't seem to understand this part: wherever there are consecutive symbols ARAfRf with Rf having a strictly bigger base value than R. What does it mean exactly?

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