F digital_root(=n)
   V ap = 0
   L n >= 10
      n = sum(String(n).map(digit -> Int(digit)))
      ap++
   R (ap, n)

L(n) [Int64(627615), 39390, 588225, 393900588225, 55]
   Int64 persistance, root
   (persistance, root) = digital_root(n)
   print(‘#12 has additive persistance #2 and digital root #..’.format(n, persistance, root))