Roman Numerals to Integer Conversion

Given a string representing a Roman numeral, your task is to convert it to its integer representation. The Roman numeral will be a valid numeral in the range from 1 to 3999.

The numbers are represented by the following symbols:

• I : 1
• V : 5
• X : 10
• L : 50
• C : 100
• D : 500
• M : 1000

Typically, Roman numerals are written largest to smallest from left to right. However, if a smaller numeral appears before a larger numeral, it is subtracted. In mathematical terms, for any two symbols s_i and s_{i+1}, if value(s_i) < value(s_i+1), then it contributes -value(s_i); otherwise, it contributes +value(s_i). This rule can be expressed in LaTeX as:

$$\text{result} = \sum_{i=1}^{n} \begin{cases} value(s_i) & \text{if} \; i=n \; \text{or} \; value(s_i) \geq value(s_{i+1}) \\- value(s_i) & \text{if} \; value(s_i) < value(s_{i+1}) \end{cases}$$

Your program should read the Roman numeral from standard input and output the corresponding integer to standard output.

inputFormat

The input consists of a single line containing a valid Roman numeral string s.

You should read the input from standard input (stdin).

outputFormat

Output a single integer, which is the numerical value of the Roman numeral.

The output should be written to standard output (stdout).

## sample

III

3