'use strict'

const main = input => {
	const args = input.split('\n').map(arg => arg.split(' '))
	const A = parseInt(args[0][0], 10)
	const B = parseInt(args[0][1], 10)
	const t1 = A + B
	const t2 = A - B 
	const t3 = A * B
	console.log(Math.max(t1, t2, t3))
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'))
