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 \(ARARAR \dots AR\) , where each \(A\) is an Arabic digit, and each \(R\) is a Roman numeral. Each pair \(AR\) 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 \(A\) can be 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9. A Roman numeral \(R\) is one of the seven letters I, V, X, L, C, D, or M. Each Roman numeral has a base value:

The value of a pair \(AR\) is \(A\) times the base value of \(R\) . Normally, you add up the values of the pairs to get the overall value. However, wherever there are consecutive symbols \(ARA^{\prime}R^{\prime}\) with \(R^{\prime}\) having a strictly bigger base value than \(R\) , the value of pair \(AR\) must be subtracted from the total, instead of being added .

For example, the number \(3M1D2C\) has the value \(3 \times 1000 + 1 \times 500 + 2 \times 100 = 3700\) and \(3X2I4X\) has the value \(3 \times 10 - 2 \times 1 + 4 \times 10 = 68\) .

Write a program that computes the values of aromatic numbers.

Input Specification

The input is a valid aromatic number consisting of between \(2\) and \(20\) 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