#!/bin/bash

set -eu

main() {
	local targ="$1"
	shift
	local vals="$@"

	#echo "solving for $targ using $vals"

	for v in $vals ; do
		if [[ $v == $targ ]] ; then
			echo won
			return 0
		fi
	done

	if [[ $# < 2 ]] ; then
		#echo "out of options"
		return 1
	fi

	declare -i i
	declare -i j
	declare -i k
	for (( i=1 ; i <= $# ; i++ )) ; do
		for (( j=$i ; j <= $# ; j++ )) ; do
			if [[ $i == $j ]] ; then
				continue
			fi

			declare -i iv=${!i}
			declare -i jv=${!j}

			local others=''
			for (( k=1 ; k <= $# ; k++ )) ; do
				if [[ $i == $k || $j == $k ]] ; then
					continue
				fi
				local kv=${!k}
				others="$others $kv"
			done

			if main $targ $others $(($iv + $jv)) ; then
				echo $iv + $jv = $(($iv + $jv))
				return 0
			fi
			if main $targ $others $(($jv - $iv)) ; then
				echo $jv - $iv = $(($jv - $iv))
				return 0
			fi
			if main $targ $others $(($iv - $jv)) ; then
				echo $iv - $jv = $(($iv - $jv))
				return 0
			fi
			if main $targ $others $(($iv * $jv)) ; then
				echo $iv x $jv = $(($iv * $jv))
				return 0
			fi

			if [[ $jv != 0 && $(( $iv % $jv )) == 0 ]] && \
			   main $targ $others $(($iv / $jv)) ; then
				echo $iv / $jv = $(($iv / $jv))
				return 0
			fi
			if [[ $iv != 0 && $(( $jv % $iv )) == 0 ]] && \
			   main $targ $others $(($jv / $iv)) ; then
				echo $jv / $iv = $(($jv / $iv))
				return 0
			fi
		done
	done

	#echo "no solution"
	return 1
}

main "$@"