#!/bin/bash

program=''
input=$1
input_i=0
while read line; do
  case $line in
    "inp"*)
      program="${program}${line:4}"'=${input:$input_i:1};input_i=$((input_i+1));'
      ;;
    "add"*)
      program="${program}${line:4:1}="'$(('"${line:4:1}+${line:6}"'))'";"
      ;;
    "mul"*)
      program="${program}${line:4:1}="'$(('"${line:4:1}*${line:6}"'))'";"
      ;;
    "div"*)
      program="${program}${line:4:1}="'$(('"${line:4:1}/${line:6}"'))'";"
      ;;
    "mod"*)
      program="${program}${line:4:1}="'$(('"${line:4:1}%${line:6}"'))'";"
      ;;
    "eql"*)
      program="${program}${line:4:1}="'$(('"${line:4:1}==${line:6}"'))'";"
      ;;
  esac
done

w=0
x=0
y=0
z=0
eval $program

echo w=$w
echo x=$x
echo y=$y
echo z=$z