#include <stdio.h>

int randomate ( int seed, int tap1, int tap2, int l )
{
  int i;

  for (i=0; i<l; i++ ) {
    int t1=((tap1&seed)!=0);
    int t2=((tap2&seed)!=0);

    seed=(seed>>1) | ((t1^t2) << (l-1));
  }
  return seed;
}

int main ( int argc, char **argv )
{
  int seed;
  int i, j, tap0, tap1, l=16;

  seed=0xffff;
  tap0=0x0001;
  tap1=0x0010;

  for (i=0; i<(1<<(l+1)); i++ ) {
    seed=randomate ( seed, tap1, tap0, l );
    if (seed == 0) {
      printf ("seed became 0\n" );
      exit(0);
    }
  }
  return 0;
}