Sum of Consecutive Integers

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Time limit0.25sMemory limit128 MB

Summary

Given two integers, print the sum of all integers in the closed range between them, handling either order.

Level: Easy2 of 10
Topics: Math, Implementation
Solved: No attempts yet

Problem

Given two integers A and B, compute the sum of every integer between them, including both endpoints. A may be greater than B; in that case, still sum every integer in the closed interval between the two values.

Input

The first line contains two integers A and B separated by a space.

-2,147,483,648 ≤ A, B ≤ 2,147,483,647

Output

Print the sum of every integer between A and B on the first line. The output value is guaranteed to be between -2,147,483,648 and 2,147,483,647, inclusive.

Examples1

Example 1
Input
```
1 2
```
Expected output
```
3
```