# Write a program to calculate the GCD of given numbers using recursion

**How to find GCD:-**

The Greatest Common Divisor (GCD) for 8, and 12, notation CGD(8,12), is 4.

Explanation:

- The factors of 8 are 1,2,4,8;
- The factors of 12 are 1,2,3,4,6,12;
- So greatest common divisor is 4.

__Code:-__

#include<stdio.h>

// function for calculating the GCD

int GCD(int a,int b,int n)

{

if( a%n==0 && b%n==0)

return n;

else

{

n=n–1;

GCD(a,b,n);

}

}

int main()

{

int a,b,n,g;

printf(“Enter two numbern”);

scanf(“%d%d”,&a,&b);

n=a>b?b:a; // for finding greater number

g=GCD(a,b,n); // function calling

printf(“GCD of the numbers is: %d”,g);

return 0;

}

**–**

__Output:__Enter two number

12 8

GCD of the numbers is: 4