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2346.   Gauß in Elementary School
Time Limit: 1.0 Seconds   Memory Limit: 65536K
Total Runs: 2284   Accepted Runs: 977

Johann Carl Friedrich Gauß(1777-1855) was one of the most important German mathematicians . For those of you who remember the Deutsche Mark, a picture of him was printed on the 10,-DM bill. In elementary school, his teacher J. G. Buttner tried to occupy the pupils by making them add up the integers from 1 to 100. The young Gauß surprised everybody by producing the correct answers (5050) within seconds.

Can you write a computer program that can compute such sums really quickly?

### Problem

Given two integers n and m, you should compute the sum of all the integers from n to m. In other words, you should compute

 Σ m i     =     n + (n + 1) + (n + 2) + ... + (m - 1) + m i = n

### Input

The first line contains the number of scenarios. Each scenario consists of a line containing the numbers n and m (-109nm ≤ 109).

### Output

The output for every scenario begins with a line containing "Scenario #i:", where i is the number of the scenario starting at 1. Then print the sum of all integers from n to m. Terminate the output for the scenario with a blank line.

### Sample Input

3
1 100
-11 10
-89173 938749341


### Sample Output

Scenario #1:
5050

Scenario #2:
-11

Scenario #3:
440625159107385260



Source: TUD Programming Contest 2006
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