BYTE FUNC P(CARD y)
RETURN ((y+(y/4)-(y/100)+(y/400)) MOD 7)

BYTE FUNC IsLongYear(CARD y)
  IF P(y)=4 OR P(y-1)=3 THEN
    RETURN (1)
  FI
RETURN (0)

PROC Main()
  CARD y
  BYTE LMARGIN=$52,oldLMARGIN

  oldLMARGIN=LMARGIN
  LMARGIN=0 ;remove left margin on the screen
  Put(125) PutE() ;clear the screen

  FOR y=1900 TO 2400
  DO
    IF IsLongYear(y) THEN
      PrintC(y) Put(32)
    FI
  OD

  LMARGIN=oldLMARGIN ;restore left margin on the screen
RETURN