B"You can never buy enough happiness, so here we go again! In this version, you can only buy h_i = 1 unit of happiness each month, but the number of months is hugely increased. We are in the realm of quantum happiness and time dilation. Being a physicist, Charlie likes to plan his life in simple and precise terms. For the next m months, starting with no money, Charlie will work hard and earn x pounds per month. For the i -th month (1 <= i <= m) , there'll be a single opportunity of paying cost c_i pounds to obtain one unit of happiness. You cannot buy more than one unit each month. Borrowing is not allowed. Money earned in the i -th month can only be spent in a later j -th month ( j>i ). Since physicists don't code, help Charlie find the maximum reachable units of happiness. The first line of the input contains t ( 1 <= q t <= q 10^4 ) -- the number of test cases. The first line of each test case contains two integers, m and x ( 1 <= m <= 2 cdot 10^5 , 1 <= x <= 10^3 ) -- the total number of months and the monthly salary. The second line of each test case contains m integers c_1, c_2, ... , c_m ( 1 <= q c_i <= q 10^3 ) -- the cost of one unit of happiness for each month. It is guaranteed that sum of m over all test cases does not exceed 2 cdot 10^5 . For each test case, output one integer -- the maximal amount of happiness Charlie can get. "...