namespace Gcd
{
	public abstract class PairWithGcdR
	{ 
		protected int	p,
						q;

		public int P {get {return p;}}
		public int Q {get {return q;}}

		public virtual void Set (int p, int q) 
		{
			this.p = p;
			this.q = q;
		}

		public abstract int Gcd ();
	}
}