def square(x : Double) = x * x
def sumOfSquares(x : Double, y : Double) = square(x) + square(y)

def sumOfSquares2(x : Double, y : => Double) = square(x) + square(y)

def factorial(n: Int): Int =
	if(n == 0 ) 1 else n * factorial(n-1)

def gcd(a: Int, b: Int): Int = 
	if(b == 0) a else gcd(b, a%b)