static RomanPattern()
{
I = new RomanPattern('I', 1);
V = new RomanPattern('V', 5, I);
X = new RomanPattern('X', 10, I);
L = new RomanPattern('L', 50, X);
C = new RomanPattern('C', 100, X);
D = new RomanPattern('D', 500, C);
M = new RomanPattern('M', 1000, C);
}
public RomanPattern(char ch, int unit, RomanPattern prefix = null)
{
Character = ch;
Unit = unit;
Prefix = prefix;
}