function romToDec (roman$)
    num = 0
    prenum = 0
    for i = length(roman$) to 1 step -1
        x$ = mid(roman$, i, 1)
        n = 0
        if x$ = "M" then n = 1000
        if x$ = "D" then n = 500
        if x$ = "C" then n = 100
        if x$ = "L" then n = 50
        if x$ = "X" then n = 10
        if x$ = "V" then n = 5
        if x$ = "I" then n = 1

        if n < preNum then num -= n else num += n
        preNum = n
    next i

    return num
end function

#Testing
print "MCMXCIX = "; romToDec("MCMXCIX")     #1999
print "MDCLXVI = "; romToDec("MDCLXVI")     #1666
print "XXV     = "; romToDec("XXV")         #25
print "CMLIV   = "; romToDec("CMLIV")       #954
print "MMXI    = "; romToDec("MMXI")        #2011