alsomagic often has unexpected gains from his strolling around.
One day, he found a magical machine, on which there was an expression "Automatic Card-interpret Machine (ACM)-TYPE N". Oh.....it was a machine used to read cards. beside of the ACM, there were a great many cards labeled 0, 1, 2 ... alsomagic counted it again and again, then found the total of them is 2^N...oh, good heavens! What were they used to do?
Piquant alsomagic was so curious that he put a card with number k into ACM, but the machine showed that he must input the passwords! alsomagic had no idea. So he guest and try some number, wonder happened---he shoot it!!! A beautiful photo of a ppmm came out from the ACM... So pp ...
alsomagic was very exited and he was so careful that he found some words on the screen:" The password of card k/2 + (k%2)*2^(N-1) is XXXXXX." By seeing these alsomagic put the card whose number is k/2 + (k%2)*2^(N-1) into ACM and another photo of ppmm appeared! And some other words were shown on the screen too:" The password of... "
How many cards' password should poor alsomagic at least know if he wanted to see all of the photos?
Input
This problem consists of several test cases. Each case consists of exactly one line containing an integer N (0 < N <= 200), which indicates the ACM's type. A case with N = 0 means the end of test, which should not be proceeded.
Output
For each test case you should just output a single number perline.
Sample Input
2
3
0
Sample Output
3
4