I would like to congratulate all participants, but specially to Rick for winning the second problem and for achieve a fantastic performance. From my side, I am happy to have obtained the third position. My trial division algorithm is nothing special, and even when some improvements can double its speed (gross estimation), it is not good enough to beat Rick's solution. Vovanx86 also did a fantastic job, and there are also some very fast solutions who did not get a better result because of correctness problems.
Once again, Congratulation to everybody. Good job:o)