Program	test
	implicit none
	real*8 RF
!   Generate a number between 1 and 12
	Do 
	write(*,*) int(1+RF(0)*12)
	pause

	end do
	
	end program
!***********************************************************************
	REAL*8 FUNCTION RF(IDUM)
 !--generates a uniformly distributed random fraction between 0 and 1
!----IDUM will generally be 0, but negative values may be used to  re-initialize the seed
      SAVE MA,INEXT,INEXTP
      PARAMETER (MBIG=1000000000,MSEED=161803398,MZ=0,FAC=1.E-9)
      DIMENSION MA(55)
      DATA IFF/0/
      IF (IDUM.LT.0.OR.IFF.EQ.0) THEN
        IFF=1
        MJ=MSEED-IABS(IDUM)
        MJ=MOD(MJ,MBIG)
        MA(55)=MJ
        MK=1
        DO 50 I=1,54
          II=MOD(21*I,55)
          MA(II)=MK
          MK=MJ-MK
          IF (MK.LT.MZ) MK=MK+MBIG
          MJ=MA(II)
50      CONTINUE
        DO 100 K=1,4
          DO 60 I=1,55
            MA(I)=MA(I)-MA(1+MOD(I+30,55))
            IF (MA(I).LT.MZ) MA(I)=MA(I)+MBIG
60        CONTINUE
100     CONTINUE
        INEXT=0
        INEXTP=31
      END IF
200   INEXT=INEXT+1
      IF (INEXT.EQ.56) INEXT=1
      INEXTP=INEXTP+1
      IF (INEXTP.EQ.56) INEXTP=1
      MJ=MA(INEXT)-MA(INEXTP)
      IF (MJ.LT.MZ) MJ=MJ+MBIG
      MA(INEXT)=MJ
      RF=MJ*FAC
      IF (RF.GT.1.E-8.AND.RF.LT.0.99999999) RETURN
      GO TO 200
      END Function
!******************************************************************