ebartrum

#Define a function to return true if we have a digit cancelling fraction
 
"""The function will take 2 inputs: [a,b],[c,d].
It will return true if ab/cd is a digit cancelling fraction."""
 
#Define a function to return a common element of x,y
 
def commonElt(x,y):
    for z in x:
        if z in y:

ebartrum

#Define the function f by recursion:
def f(n):
    if n==1:
        return 1
    if n==3:
        return 3
    if n%2==0:
        return f(n/2)
    if (n-1)%4==0:
        m=(n-1)/4