F perta(atomic)
   -V
      NOBLES = [2, 10, 18, 36, 54, 86, 118]
      INTERTWINED = [0, 0, 0, 0, 0, 57, 89]
      INTERTWINING_SIZE = 14
      LINE_WIDTH = 18

   V prev_noble = 0
   V row = 0
   Int col
   L(noble) NOBLES
      row = L.index
      I atomic <= noble
         V nb_elem = noble - prev_noble
         V rank = atomic - prev_noble
         I INTERTWINED[row] & atomic C INTERTWINED[row] .. INTERTWINED[row] + INTERTWINING_SIZE
            row += 2
            col = rank + 1
         E
            V nb_empty = LINE_WIDTH - nb_elem
            V inside_left_element_rank = I noble > 2 {2} E 1
            col = rank + (I rank > inside_left_element_rank {nb_empty} E 0)
         L.break
      prev_noble = noble
   R (row + 1, col)

V TESTS = [
    (1, (1, 1)),
    (2, (1, 18)),
    (29, (4,11)),
    (42, (5, 6)),
    (58, (8, 5)),
    (59, (8, 6)),
    (57, (8, 4)),
    (71, (8, 18)),
    (72, (6, 4)),
    (89, (9, 4)),
    (90, (9, 5)),
    (103, (9, 18)),
]

L(input, out) TESTS
   V found = perta(input)
   print(‘TEST:#3 -> ’.format(input)‘’String(found)‘’(I found != out {‘ ; ERROR: expected ’out} E ‘’))