#!/usr/bin/ruby
# -*- coding: utf-8 -*-
=begin
ITP1_8-B
 
Character - Sum of Numbers
Time Limit : 1 sec, Memory Limit : 65536 KB
??°?????????

?????????????????°???????????????????¨??????????????????°?????????????????????????????????
Input

?????°??????????????????????????\?????¨??????????????????????????????????????????????????????????????´??° x ?????????????????§?????????????????????

x ??? 1000 ?????\????????´??°??§??????

x ??? 0 ?????¨?????\?????????????????¨??????????????????????????????????????????????????????????????£????????????????????????
Output

????????????????????????????????????x ???????????????????????????????????????????????????
Sample Input

123
55
1000
0

Sample Output

6
10
1

=end
fh=STDIN
#fh=open("IPT1_8_A.txt")
while s = fh.gets
  break if s =~ /^0$/
  puts s.split(//).map{|x| x.to_i}.inject(0) {|acc,item| acc + item}
end