#!/usr/bin/env bash
{
	echo 'h=0'
	echo 'd=0'
	cat 2.in | sed 's/forward/h+=/; s/down/d+=/; s/up/d-=/; s/^/: $((/; s/$/))/'
	echo 'echo $((h * d))'
} | bash

{
	echo 'h=0'
	echo 'a=0'
	echo 'd=0'
	cat 2.in | sed 's/forward \(.*\)/: $((h+=\1)) $((d+=a*\1))/; s/down \(.*\)/: $((a+=\1))/; s/up \(.*\)/: $((a-=\1))/'
	echo 'echo $((h * d))'
} | bash