100 :
 110  REM  100 DOORS PROBLEM
 120 :
 130  DIM D(100)
 140  FOR P = 1 TO 100
 150  FOR T = P TO 100 STEP P
 160  D(T) =  NOT D(T): NEXT T
 170  NEXT P
 180  FOR I = 1 TO 100
 190  IF D(I) THEN  PRINT I;" ";
 200  NEXT I