#!/bin/bash

points=()
while read line; do
  x1=$(sed 's/,.*$//' <<< $line)
  y1=$(sed 's/^.*,\(.*\) ->.*$/\1/' <<< $line)
  x2=$(sed 's/^.*-> \(.*\),.*$/\1/' <<< $line)
  y2=$(sed 's/^.*,.*,//' <<< $line)
  if [ $x1 -eq $x2 ]; then
    x_inc=0
  elif [ $x1 -gt $x2 ]; then
    x_inc=-1
  else
    x_inc=1
  fi
  if [ $y1 -eq $y2 ]; then
    y_inc=0
  elif [ $y1 -gt $y2 ]; then
    y_inc=-1
  else
    y_inc=1
  fi
  i=$x1
  j=$y1
  while [ $i -ne $x2 ] || [ $j -ne $y2 ]; do
    points+=( "$i,$j" )
    i=$((i+x_inc))
    j=$((j+y_inc))
  done
  points+=( "$i,$j" )
done

printf '%s\n' "${points[@]}" | sort | uniq -d | wc -l