PROGRAMMING:5-1 to calculate the sum of 1 + 2 + 3 +... + n

5-1 calculates the sum of sum = 1 + 2 + 3 + 4 +... + N, where n is entered from the keyboard.
###Input format:
For example, enter a positive integer.
###Output format:
For example: output and.
###Input example:
Here is a set of inputs. For example:
```in
one hundred
```
###Output example:
The corresponding output is given here. For example:
```out
five thousand and fifty
```







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