let arr=readLine()!.characters.split{$0==" "}.map{Int(String($0))!}

let plus  = arr[0] + arr[1]
let minus = arr[0] - arr[1]
let mul   = arr[0] * arr[1]

var o = plus

if ( o < minus ) {
  o = minus
}

if ( o < mul ) {
  o = mul
}

print( o )
