program if
	nitems = 0
	total = 0.0
	print *, ' Enter integers one at a time in the range 0 to 500'
	print *, ' Type 99999 to finish'
C
C Prompt for and accept numbers
C
    1   print *, ' Number please:'
        read *, n
        if (n.eq. 99999) then
       		print *, ' End of data entry'
       		xmean = total/nitems
       		print *, ' Sum = ', total
       		print *, ' Mean = ', xmean
       		print *, ' Number of valid data items = ', nitems
       		stop
	else if (n.gt. 500) then
		print *, ' This number is TOO LARGE'
	else if (n.lt.0) then
		print *, ' This number is too SMALL'
	else 
		nitems = nitems + 1
		total = total + n
	end if
	goto 1
	end