The point of a lot of these challenges is to be smart with your math as well as your code. A brute force approach isn't going to work very well, especially in this case. An integer with 7^20 trailing zeros isn't even going to fit in your RAM.
An observation: every trailing zero implies a factor of ten, which in primes is two and five. So the final number will have at least 7^20 twos and fives in its prime factorization. Exploiting this fact in a clever way is probably one way to solve this problem. Cheers _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
