Problem:
Score : 300 points

Problem Statement

There is a rectangle in a coordinate plane. The coordinates of the four vertices are (0,0), (W,0), (W,H), and (0,H).
You are given a point (x,y) which is within the rectangle or on its border. We will draw a straight line passing through (x,y) to cut the rectangle into two parts. Find the maximum possible area of the part whose area is not larger than that of the other. Additionally, determine if there are multiple ways to cut the rectangle and achieve that maximum.

Constraints

1 \leq W,H \leq 10^9

0\leq x\leq W

0\leq y\leq H

All values in input are integers.

Input

Input is given from Standard Input in the following format:

W H x y

Output

Print the maximum possible area of the part whose area is not larger than that of the other, followed by 1 if there are multiple ways to cut the rectangle and achieve that maximum, and 0 otherwise.

The area printed will be judged correct when its absolute or relative error is at most 10^{-9}.

Sample Input 1

2 3 1 2

Sample Output 1

3.000000 0

The line x=1 gives the optimal cut, and no other line does.

Sample Input 2

2 2 1 1

Sample Output 2

2.000000 1

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;

public static partial class Program
{
    public static void Main()
    {
        var whxy = CRL().ArrayInts();
        var w = whxy[0];
        var h = whxy[1];
        var x = whxy[2];
        var y = whxy[3];

        var menseki = (double) w * h / 2;

        var hukusuu = 0;
        if (x != 0 && y != 0)
        {
            if (w == x * 2 && h == y * 2)
            {
                hukusuu = 1;
            }
        }

        CWL($"{menseki} {hukusuu}");
    }
}

public static partial class Program
{
    //テンプレここから
    public static int Sigma(int n, int next = 1, int val = 0) => next > n ? val : Sigma(n, next + 1, val + next);
    public static long GCD(long a, long b) => b == 0 ? a : GCD(b, a % b);
    public static int GCD(int a, int b) => b == 0 ? a : GCD(b, a % b);
    public static long LCM(long a, long b) => a * b / GCD(a, b);
    public static int LCM(int a, int b) => a * b / GCD(a, b);
    public static string CRL() => Console.ReadLine();
    public static void CWL(object obj) => Console.WriteLine(obj);
    public static int ToInt(this double d) => (int) d;
    public static long ToLong(this double d) => (long) d;
    public static int ToInt(this string str) => int.Parse(str);
    public static long ToLong(this string str) => long.Parse(str);
    public static long[] ToLong(this IEnumerable<string> strs) => strs.Select(x => x.ToLong()).ToArray();
    public static int[] ToInt(this IEnumerable<string> strs) => strs.Select(x => x.ToInt()).ToArray();
    public static long[] ArrayLongs(this string str, char opr = ' ') => str.Split(opr).ToLong();
    public static int[] ArrayInts(this string str, char opr = ' ') => str.Split(opr).ToInt();
    public static long Diff(long a, long b) => Math.Abs(Math.Max(a, b) - Math.Min(a, b));
    public static int Diff(int a, int b) => Math.Abs(Math.Max(a, b) - Math.Min(a, b));
    public static long Sign(this long i) => Math.Sign(i);
    public static bool IsEven(this long i) => i % 2 == 0;
    public static bool IsEven(this int i) => i % 2 == 0;
    public static readonly int[] Dx = {0, -1, 0, 1};
    public static readonly int[] Dy = {-1, 0, 1, 0};
    public const int Mod = 1000000007;
    public static string alphabet = "abcdefghijklmnopqrstuvwxyz";
    public static long ToLong(this char c) => c.ToString().ToLong();
    public static int ToInt(this char c) => c.ToString().ToInt();
    public static long[] Sort(this long[] array) => array.OrderBy(x => x).ToArray();
    public static int[] Sort(this int[] array) => array.OrderBy(x => x).ToArray();
    public static long[] DSort(this long[] array) => array.OrderByDescending(x => x).ToArray();
    public static int[] DSort(this int[] array) => array.OrderByDescending(x => x).ToArray();
    public static string Join(this IEnumerable<string> array, string sep = "") => string.Join(sep, array);
    public static string Join(this IEnumerable<char> array, string sep = "") => string.Join(sep, array);

    public static string JoinToStr(this IEnumerable<int> array, string sep = "")
        => array.Select(x => x.ToString()).Join(sep);

    //テンプレここまで
}