FORTRAN PROGRAM 1. Solution of Simpson's 1/3 Rule

Q. write a program using fortran to find area using simpson's 1/3 rule
A.
 program simp3
       implicit none
       integer :: n,i
       real :: h,y,y1,ylast,s,a
       write(*,*) "Enter Number of trems"
       read(*,*) n
       write(*,*) "Enter Step size"
       read(*,*) h
       write(*,*) "Enter first term"
       read(*,*) y1
       write(*,*) "Enter last term"
       read(*,*) ylast
       s=y1+ylast
       do  i=2,n-1
       write(*,*) "enter y",i,"th term"
       read(*,*) y
       continue
       IF(mod(i,2).EQ.0) then
          s=s+4*y
          else
          s=s+2*y
       end IF
       end do
       a=h*s/3
       write(*,*) "area is :-  ",a
       read(*,*)
       end program simp3