Please write in C language.

The greatest common divisor of integers x and y is the largest integer that evenly divides both x and y. Write a recusrice function gcd that returns the greatest common divisor of x and y. The gcd of x and y is defiend recursively as follows: if y is equal to 0, then gcd(x,y) is x; otherwise gcd(x,y) is gcd(y,x%y) where % is the remanded operator