program procgcdinput{

	int gcd(int a, int b)
	{
		while (a != b) {
			if (a>b) 
				a = a-b;
			if (a<b)
				b = b-a;
		}
		return a;
	}
	
	void main()
		int a;
		int b;
	{
		print(gcd(12,8),3);
	}
}