PROGRAMMING:Licensing

After Hu Junjie bought the Kuluo card, he would distribute it to his friends. On the first day, the little partner received a card; The next two days (the second and third days), received 2 cards a day; The next three days (the fourth, fifth and sixth days), I received three cards a day; The next four days (the seventh and ninetieth days), received four cards per day; This kind of licensing will continue. When you receive $$n $$Kulo cards for $$n $$days in a row, you will receive $$n + 1 $$Kulo cards every day for the following $$n + 1 $$days.
###Input format:
Enter the number of days n of licensing in the first line
###Output format:
The output only contains a positive integer in one line, that is, the total number of playing cards received by the small partners
###Input example:
```in
six
```
###Output example:
The corresponding output is given here. For example:
```out
fourteen
```







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