PROGRAM:ROM2DEC
:Input "ROMAN:",Str1
:{1000,500,100,50,10,5,1}➞L1
:0➞P
:0➞Y
:For(I,length(Str1),1,-1)
  :inString("MDCLXVI",sub(Str1,I,1))➞X
  :If X≤0:Then
    :Disp "BAD NUMBER"
    :Stop
  :End
  :L1(x)➞N
  :If N<P:Then
    :Y–N➞Y
  :Else
    :Y+N➞Y
  :End
  :N➞P
:End
:Disp Y