#coprime test
def gcd(m,n):
q = m%n
if q ==0:
return n
else:
return gcd(n, q)
def iscoprime(a,b):
return gcd(a,b) == 1
without recursion,
def gcd(m,n):
#[n, m] = sorted([a,b])
while m%n != 0:
m, n = n, m-n*(m/n)
return n