GCD using recursion

GCD using recusion
what is recursion?
GCD using Euclidean algorithm
def gcd(num1,num2):
        if (num2==0):
              return num1
        return gcd(num2,num1%num2)

x=int(input("enter 1st number "))
y=int(input("enter 2nd number "))
s=str(gcd(x,y))
print("gcd is "+s)