cobol

IDENTIFICATION DIVISION.
PROGRAM-ID. WEEKLY-SALES.

DATA DIVISION.
WORKING-STORAGE SECTION.
01 TOTAL-SALES PIC 9(7)V99 VALUE 0.
01 DAILY-SALES PIC 9(7)V99 VALUE 0.
01 DAY-COUNTER PIC 9 VALUE 1.

PROCEDURE DIVISION.
BEGIN.
DISPLAY "Weekly Sales Calculator".
DISPLAY "Enter the sales for 7 days one by one:".

PERFORM UNTIL DAY-COUNTER > 7
    DISPLAY "Enter sales for Day " DAY-COUNTER ": "
    ACCEPT DAILY-SALES
    IF DAILY-SALES < 0 THEN
        DISPLAY "Invalid input: Sales cannot be negative. Please re-enter."
    ELSE
        DISPLAY "Sales for Day " DAY-COUNTER " is $" DAILY-SALES
        ADD DAILY-SALES TO TOTAL-SALES
        ADD 1 TO DAY-COUNTER
    END-IF
END-PERFORM.

DISPLAY "--------------------------------------".
DISPLAY "Total sales for the week: $" TOTAL-SALES.
STOP RUN.