IDENTIFICATION DIVISION.
PROGRAM-ID. 171C.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 N          PIC  9(16) COMP.
01 M          PIC  9(16) COMP.
01 AMR        PIC  9(02) COMP.
01 ALPHA      PIC  X(26) VALUE 'abcdefghijklmnopqrstuvwxyz'.
01 I          PIC  9(04) COMP.
01 OUT        PIC  X(12).
*> 
PROCEDURE DIVISION.                          
  ACCEPT N.
*>
  MOVE SPACE TO OUT.
  MOVE N     TO M.
  PERFORM VARYING I FROM 12 BY -1 UNTIL M = 0
    COMPUTE M = M - 1
    DIVIDE M BY 26 GIVING M REMAINDER AMR
    ADD 1 TO AMR
    MOVE ALPHA(AMR:1) TO OUT(I:1)
  END-PERFORM
*>
  DISPLAY FUNCTION TRIM(OUT).
  STOP RUN.
