swift 최소직사각형

func solution(_ sizes:[[Int]]) -> Int {
    var array1 = [Int]()
    var array2 = [Int]()
    for i in sizes {
        let newArray = i.sorted()
        array1.append(newArray.first!)
        array2.append(newArray.last!)
    }
    return array1.max()! * array2.max()!
}