program polinomio
implicit none

integer:: n,i,ierr
real,allocatable,dimension(:)::a
real ::x,y
character (len=30)::nomefile

22 write(6,*)'Nome file dei coefficienti :'
read(5,'(a)')nomefile
open(unit=50,file=nomefile,status='old',err=22)

read(50,*)n

allocate (a(n))

do i=1,n 
   read(50,*) a(i)
enddo
close(50)

23 write(6,*)'Nome file degli X :'
read(5,'(a)')nomefile
open(unit=55,file=nomefile,status='old',err=23)

24 write(6,*)'Nome file output :'
read(5,'(a)')nomefile
open(unit=60,file=nomefile,status='new',err=24)

read(55,*,iostat=ierr) x
do while(ierr == 0)
! calcolo pol(x)

   y=0
   do i=1,n
      y=y+a(i)*x**(i-1)
   enddo

   write(60,'(2f12.3)')x,y
   read(55,*,iostat=ierr) x
enddo
if (ierr > 0) then
   write(6,*)'Errore numero:', ierr
endif

deallocate (a)
close(55)

end program polinomio