One line with a positive number: the number of test cases (at most 25). Then for each test case:

- One line with an integer N, 2 ≤ N ≤ 500, the number of points, and an integer L, 1 ≤ L ≤ 10 000, the necessary length to flatten.
- lines with two integers xi and yi with 0 ≤ xi, yi ≤ 10 000 describing the landscape of Lineland. The xi are in (strictly) ascending order. At position xi the height of the landscape is yi. Between two xi the landscape has constant slope. (So the landscape is piecewise linear). The difference between xN and x1 is greater than or equal to L.