Answer No : 15 :
n1=int(input("Enter first number"))
n2=int(input("Enter second number"))
if n2>n1:
    min=n1
else:
    min=n2
for x in range(1,min+1):
    if(n1%x==0) and (n2%x==0):
        gcd=x
print("GCD is:",gcd)
Output:
Enter first number15
Enter second number15
GCD is: 15