!
! This program written by Clint Whaley for CS 1073.  It is an optional
! programming exercise given on 9/29/09.
!
PROGRAM sumloop
!
!  This program prints out the sum of all integers between an initial starting
!  value (BEG) and an ending value (END) inclusive.
!
   IMPLICIT NONE
   INTEGER :: i, beg, end, sum
!
!  Get the beginning and end numbers, and an increment.  The asg in class
!  said use a constant increment of 3, but I decided to generalize
!
   PRINT *, 'Enter the number to begin summation at:'
   READ *, beg
   PRINT *, 'Enter the number to end summation at:'
   READ *, end
!
!  Sum up all numbers [beg,end]
!
   sum = 0
   DO i = beg, end
      sum = sum + i
   END DO

   PRINT *, 'Sum is:', sum

END PROGRAM sumloop