Nguồn: https://www.codechef.com
In Byteland they have a very strange monetary
system.
Each Bytelandian gold coin has an integer number
written on it. A coin n can be exchanged in a bank into three coins: n/2, n/3
and n/4. But these numbers are all rounded down (the banks have to make a
profit).
You can also sell Bytelandian coins for American
dollars. The exchange rate is 1:1. But you can not buy Bytelandian coins.
You have one gold coin. What is the maximum amount
of American dollars you can get for it?
Input
The input will contain several test cases (not more
than 10). Each testcase is a single line with a number n, 0 <= n <= 1 000
000 000. It is the number written on your coin.
Output
For each test case output a single line, containing
the maximum amount of American dollars you can make.
Example
Input:
12
2
Output:
13
2
You can change 12 into 6, 4 and 3, and then change
these into $6+$4+$3 = $13. If you try changing the coin 2 into 3 smaller coins,
you will get 1, 0 and 0, and later you can get no more than $1 out of them. It
is better just to change the 2 coin directly into $2
