'use strict'

function main(input) {

    let ary = input.split(' ').map(v => ~~v)

    let a = ary.reduce((x, y) => x + y)
    let b = ary.reduce((x, y) => x - y)
    let c = ary.reduce((x, y) => x * y)

    let ans = Number(Math.max(a, b, c))
    console.log(ans)
}

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