REM Periodic table
DIM A(7)
DIM B(7)
REM Arrays A, B.
DATA  1,  2,  5, 13, 57, 72, 89, 104
DATA -1, 15, 25, 35, 72, 21, 58,   7
REM Example elements (atomic numbers).
DATA 1, 2, 29, 42, 57, 58, 72, 89, 90, 103

GOSUB SetAB:
FOR J = 0 TO 9
  READ AtomicNum
  GOSUB ShowRowAndColumn:
NEXT J
END

SetAB:
FOR I = 0 TO 7
  READ A(I)
NEXT I
FOR I = 0 TO 7
  READ B(I)
NEXT I
RETURN

ShowRowAndColumn:
I = 7
WHILE A(I) > AtomicNum
  I = I - 1
WEND
M = AtomicNum + B(I)
R = M / 18
R = R + 1
C = M MOD 18
C = C + 1
PRINT AtomicNum;
PRINT " ->";
PRINT R;
PRINT C
RETURN