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. Büttner 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?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

The first line contains the number of scenarios. Each scenario consists of a line containing the numbers *n* and *m* (−10^{9} ≤ *n* ≤ *m* ≤ 10^{9}).

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