#!/bin/sh
read x
minus=0
first=1
if [[ $x == -* ]]; then minus=1; fi
sum=0
#if [[ $minus == 1 && $first == 1 ]]; then sum=$((sum-x%10));else sum=$((sum+x%10)) ; fi
for((;x!=0;)); do echo $((x%10)); if [[ $minus == 1 && $first == 1 ]]; then sum=$((sum-x%10)); first=0; minus=0; x=$((x*-1));else sum=$((sum+x%10)) ; fi;x=$((x/10)); done
echo $sum