//最大公約数(GCD)の計算
public class GCD{
 public static void main (String[] args) 
{ int P, Q, R;
  P = 31*53;
  Q = 31*101;
  R = GCD(P, Q);
  System.out.println("P="+P+" Q="+Q);
  System.out.println("gcd(P,Q)="+R); 
}
//=====================================C
 public static int GCD(int P, int Q)
{ if(Q == 0) return P;
  return GCD(Q, P%Q);  }
}