a2r(a)=
  r = ""
  n = [["M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"],[1000,900,500,400,100,90,50,40,10,9,5,4,1]]
  > i, 1..13
    > a!<n[i,2]
      r += n[i,1]
      a -= n[i,2]
    <
  <
  <= r
.

t = [1990,2008,1666]
> i, 1..#.size(t,1)
  #.output(t[i]," = ",a2r(t[i]))
<