program magnitude
      implicit none
      integer, parameter :: ikind=selected_real_kind(p=15)
      integer i,maxpower,response
     
  
      print *,'Effect of magnitude on integer, real or extended precision'
      print *,'Type 1 for integer, 2 for real or 3 for extended precision'
      read  *, response
      print *,'Enter the maximum power'
      read *,maxpower
      
      do i=1,maxpower
        if (response==1) then
           print *,i,2**i
        else if (response==2) then
           print *,i,2.0**i   
        else if (response==3) then
            print *,i,2.0_ikind**i
        else
            print *,'invalid response'
            stop
        end if
      end do
      end program magnitude