def debug(f):
    def g(x):
        y = f(x)
        print ("Računamo f({0}) --> {1}".format(x, y))
        return y
        
    return g

@debug
def fib(n):
    if n == 0 or n == 1:
        return n
    else:
        return fib(n-1) + fib(n-2)

print (fib(10))