PROGRAMMING:Calculation of number

We need to find the number with the following properties (including the natural number n of input)
First, enter a natural number n ($$n / le1000 $$), and then process the natural number as follows:
Without any treatment;
Add a natural number to the left of it, but the natural number cannot exceed half of the original number;
After adding the number, continue to process according to this rule until the natural number can not be added
###Input format:
1 natural number n ($$n / le1000 $$)
###Output format:
1 integer, which represents the number with the property.
###Input example:
```in
six
```
###Output example:
```out
six
```







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