IDENTIFICATION DIVISION.
       PROGRAM-ID. day_03_part2.
       AUTHOR. Trey Bastian.
       ENVIRONMENT DIVISION.
       INPUT-OUTPUT SECTION.
       FILE-CONTROL.
       SELECT input-file ASSIGN TO "./input.txt"
           ORGANIZATION IS LINE SEQUENTIAL.
       DATA DIVISION.
       FILE SECTION.
       FD input-file.
       01 input-line PIC Z(4096). 
       WORKING-STORAGE SECTION.
       01 idx PIC 9(4) VALUE 1.
       01 idx-2 PIC 9(4).
       01 len PIC 9(4).

       01 maxim PIC 9 VALUE 0.
       01 digit PIC 9 VALUE 0.
       01 remaining PIC 99 VALUE 12.
       01 rem-idx PIC 99 VALUE 1.

       01 joltage PIC X(12).
       01 result PIC 9(32) VALUE 0.

       
       01 eof PIC X.
           88 eof-y VALUE "Y".
           88 eof-n VALUE "N".

       PROCEDURE DIVISION.
         OPEN INPUT input-file.
         SET eof-n to TRUE.
         PERFORM UNTIL eof-y
             READ input-file AT END
                 SET eof-y to TRUE
             NOT AT END
                MOVE FUNCTION LENGTH(FUNCTION TRIM(input-line)) TO len
                MOVE 1 TO idx
                MOVE 12 TO remaining
                MOVE 1 TO rem-idx
                PERFORM UNTIL remaining < 1
                  MOVE 0 TO maxim
                  PERFORM VARYING idx FROM idx UNTIL idx > 
                    (len - remaining + 1)
                    MOVE FUNCTION NUMVAL(input-line(idx:1)) to digit
                    IF maxim < digit
                      MOVE digit TO maxim
                      MOVE idx TO idx-2
                    END-IF
                  END-PERFORM
                    MOVE maxim TO joltage(rem-idx:1)
                    ADD 1 TO rem-idx
                    SUBTRACT 1 FROM remaining
                    MOVE idx-2 TO idx
                    ADD 1 TO idx
                END-PERFORM
                ADD FUNCTION NUMVAL(joltage) TO result
              END-READ
         END-PERFORM.
         CLOSE input-file.
         DISPLAY result.
       STOP-RUN.