"""File:      recursive_sum_prt.py
   Purpose:   Find the sum of the first n positive integers using recursion

   Run:       python recursive_sum_prt.py

   Input:     A positive int n
   Output:    The sum of the first n positive integers.  This version
              also prints the recursive calls
"""
def rsum(val, indent):
   """ Use recursion to find the sum 1 + 2 + . . . + val"""
   indent = indent + "   "
   print indent, "val =", val
   if val == 1:
      print indent, "val =", val, ", returning", val
      return val
   else:
      sum = val + rsum(val-1, indent)
      print indent, "val =", val, ", returning", sum
      return sum

val = int(raw_input("Enter a whole number >= 1\n   "))
print
sum = rsum(val, "")
print
print "The sum of the first", val, "whole numbers is", sum