Napoleon’s Earnings

Napoleon choosed a city for Advertising his company's product. There are S streets in that city. Each day he travels one street. There are N buildings in a street which are located at points 1,2,3....N(respectively). Each building has some height(Say h meters). Napoleon stands at point 0. His height is 0.5m. Now Napoleon starts communicating with the people of each building. He can communicate with people of a particular building only if he can see that building. If he succeed to communicate with any particular building then his boss gives him Rrupees. i.e. if he communicates with K buildings in a day, then he will earn K∗Rrupees. Now Napoleon wants to know his maximum Earning for each day. Note: All the points are on Straight Line and Napoleon is always standing at point 0.

Input: First line of input contains an integer S, denoting no of streets in the city. Details for each street is described in next two lines. First line contains two integers N and R, denoting no of buildings in the Street and earning on communicating with a building. Second line contains N integers, denoting height of building.

Output: Print S Lines, each containing maximum earning in ith street.

Sample Input:

1

6 3

8 2 3 11 11 10

Sample Output:

6

Sample Input2:

1

5 12

12 20 39 45 89

Sample Output2:

60

Explanation

There is one streets in the city.

The first street has 6 buildings and the earning of Napoleon for communicating with each building is 3 Rupees.

Height of buildings are 8 2 3 11 11 10 respectively.

As Chef is standing at point 0 , he will be able to see only 1st and 4th building.

So his total earning will be 3*2=6 Rupees in that street

Similarly for 2nd street his earning will be 60 Rupees