```
# This is a code to prove that it is possible to find GCD of two numbers even
# without using any built in module
a = [int(input("Please enter the first number: "))]
b = [int(input("Please enter the second number: "))]
a = [x for x in range(1, a[0]+1) if a[0]%x == 0]
b = [x for x in range(1, b[0]+1) if b[0]%x == 0]
a = [x for x in b if x in a]
print("GCD of given numbers is:", max(a))
```

Some were not Okay with using built in module