PROGRAMMING:Daydream never thought of

Hello everyone, I'm not Wang dachui. I never thought that I was working in the company. In the process of crossing, I met God. God told me that as long as I helped him solve his problems, I would help me realize my wish. God's problem actually asked me to calculate the odd sum of less than or equal to N, such as n = 7, then the sum was 1 + 3 + 5 + 7 = 16. If I can solve this problem, it won't be long before I can raise my salary, become the general manager, become the CEO, marry Bai Fumei and go to the top of my life. Ha ha, I'm still a little excited. Smart acmer, can you help me?
###Input format:
Enter an N in each line, n is less than 50 and odd;
###Output format:
The sum of N numbers, each in a row.
###Input example:
Here is a set of inputs. For example:
```in
seven
```
###Output example:
The corresponding output is given here. For example:
```out
sixteen
```







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