const main = (a,b) => {
    r = []
    r.push(a+b)
    r.push(a-b)
    r.push(a*b)
    return Math.max(...r)
}

const input = require('fs').readFileSync('/dev/stdin','utf8').split('\n')[0].split(" ")
const ab = input.map(x => parseInt(x,10))
console.log(main(ab[0],ab[1]))
