PROGRAMMING:Garden plus

After learning how to add, garden thought it was too easy, but he could not do anything else, so he had to add it boring.
1+2+3+.....+n
###Input format:
Enter a positive integer n (n < 100000000)
###Output format:
Output the value of 1 + 2 + 3 +.... n
###Input example:
Here is a set of inputs. For example:
```in
one
two
three
```
###Output example:
The corresponding output is given here. For example:
```out
one
three
six
```







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