Greatest common divisor program

#Credits to NPTEL MOOC, Programming, Data Structures & Algorithms in 
#Python by Madhavan Mukund, Chennai Mathematical Institute 

def gcd(m,n):
  fm = []
  for i in range(1,m+1):
    if (m%i) == 0:
      fm.append(i)
  fn = []
  for j in range(1,n+1):
    if (n%j) == 0:
      fn.append(j)
  cf = []
  for f in fm:
    if f in fn:
      cf.append(f)
  return(cf[-1])