Navidur went to the carnival and played the stereotypical hit something with a big hammer as hard as you can. When he hit the platform, the puck flew up exactly ~N~ meters. Now, the carnival is actually hosted by Mr. White, so the scoring is a little strange this time around. Navidur's score is the sum of all the positive factors of ~N~. What's his score?
The input will be a single integer ~N~ ~(1 \le N \le 10^6)~.
Output the sum of the positive factors of ~N~.