If "condition" is true, statement1 and statement2 will be executed. If, after that, "condition" is still true, statement1 and statemen2 will be executed again.
That's horrible code. Indentation helps humans to read. Using END-IF instead of a full-stop/period also helps.
Since the 1985 COBOL Standard the requirements for full-stops/periods in the PROCEDURE DIVISION have been much reduced. Take advantage of that. You'll avoid many stupid errors.
Full-stop/period is required: on PROCEDURE DIVISION header; before paragraph/SECTION; to terminate paragraph/SECTION label; to terminate program.
To terminate a paragraph/SECTION and a program, include a single line with a full-stop/period in column 12, ie have no code with a full-stop/period on. It'll make life much easier.