SUB MostarPos (N)
    DIM a(7)
    RESTORE a:
    FOR x = 0 TO 7: READ a(x): NEXT x
    DIM b(7)
    RESTORE b:
    FOR x = 0 TO 7: READ b(x): NEXT x

    I = 7
    WHILE a(I) > N
    I = I - 1
    WEND
    M = N + b(I)
    R = (M \ 18) + 1
    C = (M MOD 18) + 1
    PRINT USING "Atomic number ### -> #_, ##"; N; R; C
END SUB

DIM Element(0 TO 12)
RESTORE elements
elements:
DATA 1, 2, 29, 42, 57, 58, 59, 71, 72, 89, 90, 103, 113
FOR x = 0 TO 12: READ Element(x): NEXT x

FOR I = 0 TO UBOUND(Element)
    MostarPos (Element(I))
NEXT I

a:
DATA  1,  2,  5, 13, 57, 72, 89, 104
b:
DATA -1, 15, 25, 35, 72, 21, 58,   7