PexSign

using System;

public class Program
{
	// Pex for fun always selects the first comment line.
	public static int Puzzle(int i, int j)
	{
		if(sameSign(i,j)!=sameSign2(i,j))
		{
			throw new Exception();
		}
		return i;
	}

	public static bool sameSign(int num1, int num2)
	{
		return num1 >= 0 && num2 >= 0 || num1 < 0 && num2 < 0;
	}

	public static bool sameSign2(int num1, int num2)
	{
		return (num1 ^ num2) >= 0;
	}
}