int rem3(unsigned n) {
   n = (n >> 16) + (n & 0xFFFF);
   n = (n >>  8) + (n & 0x00FF);
   n = (n >>  4) + (n & 0x000F);
   n = (n >>  2) + (n & 0x0003);
   n = (n >>  2) + (n & 0x0003);
   return (0x0924 >> (n << 1)) & 3;
}

int rem5(unsigned n) {
   n = (n >> 16) + (n & 0xFFFF);
   n = (n >>  8) + (n & 0x00FF);
   n = (n >>  4) + (n & 0x000F);
   n = (n >>  4) - ((n >> 2) & 3) + (n & 3);
   return (01043210432 >> 3 * (n + 3)) & 7;
}