#!/usr/bin/env bash

set -o errexit
set -o nounset
set -o pipefail
if [[ "${TRACE-0}" == "1" ]]; then
  set -o xtrace
fi

LINES=$(wc -l < "$1")
COLUMNS=140
mapfile -t -O 1 INPUT < "$1"
declare -a gear_ratios

find_gears ()
{
  # Find and append gear ratios to array.
  for ((line=1; line<=LINES; line++)); do
    for ((column=1; column<=COLUMNS; column++)); do
      if [[ $(arr "${line}" "${column}") =~ ^\*$ ]]; then
        declare -i ratio=1
        declare -a adjacent=()
        for ((i=column-1; i<=column+1; i++)); do # check above
          if [[ $(arr $((line-1)) "${i}") =~ ^[0-9]$ ]]; then
            number="$(arr $((line-1)) "${i}")"
            for ((j=i-1; j>i-3; j--)); do # check before i, numbers are max 3-digit
              if [[ $(arr $((line-1)) "${j}") =~ ^[0-9]$ ]]; then
                number="$(arr $((line-1)) "${j}")${number}"
              else
                break
              fi
            done
            add_to_i=0
            for ((k=i+1; k<i+3; k++)); do # check after i
              if [[ $(arr $((line-1)) "${k}") =~ ^[0-9]$ ]]; then
                number="${number}$(arr $((line-1)) "${k}")"
                add_to_i=$((add_to_i+1))
              else
                break
              fi
            done
            i=$((i+add_to_i))
            adjacent+=("${number}")
          fi
        done
        for ((i=column-1; i<=column+1; i++)); do # check below
          if [[ $(arr $((line+1)) "${i}") =~ ^[0-9]$ ]]; then
            number="$(arr $((line+1)) "${i}")"
            for ((j=i-1; j>i-3; j--)); do # check before i
              if [[ $(arr $((line+1)) "${j}") =~ ^[0-9]$ ]]; then
                number="$(arr $((line+1)) "${j}")${number}"
              else
                break
              fi
            done
            add_to_i=0
            for ((k=i+1; k<i+3; k++)); do # check after i
              if [[ $(arr $((line+1)) "${k}") =~ ^[0-9]$ ]]; then
                number="${number}$(arr $((line+1)) "${k}")"
                add_to_i=$((add_to_i+1))
              else
                break
              fi
            done
            i=$((i+add_to_i))
            adjacent+=("${number}")
          fi
        done
        if [[ $(arr "${line}" $((column-1))) =~ ^[0-9]$ ]]; then # check before gear
          number="$(arr "${line}" $((column-1)))"
          for ((i=column-2; i>column-4; i--)); do # search for beginning
            if [[ $(arr "${line}" "${i}") =~ ^[0-9]$ ]]; then
              number="$(arr "${line}" "${i}")${number}"
            else
              break
            fi
          done
          adjacent+=("${number}")
        fi
        if [[ $(arr "${line}" $((column+1))) =~ ^[0-9]$ ]]; then # check after gear
          number="$(arr "${line}" $((column+1)))"
          for ((i=column+2; i<column+4; i++)); do # search for end
            if [[ $(arr "${line}" "${i}") =~ ^[0-9]$ ]]; then
              number="${number}$(arr "${line}" "${i}")"
            else
              break
            fi
          done
          adjacent+=("${number}")
        fi
        if [[ ${#adjacent[@]} -gt 1 ]]; then
          for number in "${adjacent[@]}"; do
            ratio=$((ratio*number))
          done
          gear_ratios+=("${ratio}")
        fi
      fi
    done
  done
}

arr ()
{
  # Usage: arr LINE COLUMN
  line="$1"
  column=$(($2-1))
  if ((line<=0)) || ((line>LINES)) || ((column<0)); then
    echo -n ''
  else
    echo -n "${INPUT[${line}]:${column}:1}"
  fi
}


main ()
{
  find_gears
  sum=0
  for number in "${gear_ratios[@]}"; do
    sum=$((sum+number))
  done
  echo "${sum}"
}

main