public class PC
{
	public static boolean isOdd(int num)
	{
		boolean result;
		result = num % 2 == 0;
		return result;
	}
	
	public static boolean isPrime(int num)
	{
		boolean prime;
		prime = true;
		
		for (int ii = 2; ii < num; ii++)
		{
			if (num % ii == 0)
				prime = false;
		}
		return prime;
	}
	
	public static int gcd(int first, int second)
	{
		return -1;
	}
	
	public static int lcm(int first, int second)
	{
		int mult;
		
		mult = -1;
		
		for (int ii = first; ii <= first * second && mult == -1; ii++)
		{
			if (ii % first == 0 && ii % second == 0)
				mult = ii;
		}
			
		return mult;
	}
	
	public static String reverse(String word)
	{
		String rWord;
		rWord = "";
		
		for (int ii = word.length() - 1; ii >= 0; ii--)
		{
			rWord = rWord + word.charAt(ii);
		}
		
		return rWord;
	}
	
	public static void powers2(int exp)
	{
		int power;
		power = 1;
		
		for (int ii = exp ; ii > 0; ii--)
		{	
			System.out.println(power);
			power = power * 2;
		} 		
	}
	
	public static boolean floatEquals(float a, float b, float tol)
	{
		return false;
	}
	
	public static boolean isAlpha(char c)
	{
		boolean result;
		
		if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
			result = true;
		else result = false;
		
		return result;
	}
}