const main = stdin => {
  const input = stdin.trim().split('\n')
  const [A, B] = input[0].split(' ').map(x => parseInt(x))
  const ans = Math.max(A + B, A - B, A * B)

  if (ans === 0) {
    console.log(0)
  } else {
    console.log(ans)
  }
}


// 標準入力
main(require("fs").readFileSync("/dev/stdin", "utf8"))
