program fibonacci
      real fib1,fib2,new 
      integer n
      print*, 'Enter N:'
      read*, n
30    if (n .lt. 3)then
        print*,'error'
        print*, 'Please key in number greater or equal to 3'
        read*,n 
        goto 30
      else
        fib1=1
        fib2=1
        print*,fib1
        print*,fib2
        do i=3,n
           new=fib1+fib2
           fib1=fib2 
           fib2=new
           print*, new
        enddo
      endif
      end