public class PC
{
	public static boolean isOdd(int num)
	{
		return -1
	}
	
	public static boolean isPrime(int num)
	{
		return true;
	}
	
	public static int gcd(int first, int second)
	{
		return -1;
	}
	
	public static int lcm(int first, int second)
	{	
		return -1;
	}
	
	public static String reverse(String word)
	{
		return word;
	}
	
	public static void powers2(int exp)
	{
				
	}
	
	public static boolean floatEquals(float a, float b, float tol)
	{
		return false;
	}
	
	public static boolean isAlpha(char c)
	{
		return false;
	}
}