You are given a bag of size W kg and you are provided costs of packets different weights of oranges in array cost where cost[i] is basically cost of ‘i’ kg packet of oranges. Where cost[i] = -1 means that ‘i’ kg packet of orange is unavailable
Find the minimum total cost to buy exactly W kg oranges and if it is not possible to buy exactly W kg oranges then print -1. It may be assumed that there is infinite supply of all available packet types.
Note : array starts from index 1.
The first line of input contains an integer T denoting the number of test cases. Then T test cases follow. The first line of each test case contains integers N and W where N denotes the size of array cost[ ] and W is the size of the bag.
The second line of each test case contains N space separated integers denoting elements of the array cost[ ].
Print the minimum cost to buy exactly W kg oranges. If no such answer exists print "-1".
1<= T <=100
1<= N, W <=1000
1<= cost[ ] <=1000
20 10 4 50 100
-1 -1 4 5 -1