private static final int gcd(int a, int b)
private static int gcd(int a, int b)
  private static final int gcd(int a, int b)  {    // Euclid's algorithm, copied from libg++.    int tmp;    if (b > a)      {	tmp = a; a = b; b = tmp;      }    for(;;)      {	if (b == 0)	  return a;        if (b == 1)	  return b;        tmp = b;	    b = a % b;	    a = tmp;	  }      }