====== List Sum ====== ===== Description ===== You are given four lists A, B, C and D containing integers. All lists have the same size n. How many quadruplets (a, b, c, d) ∈ A x B x C x D exist so that a+b+c+d = 0? ===== Input ===== The input begins with a single positive integer T on a line by itself indicating the number of the cases following, each of them as described below. This line is followed by a blank line, and there is also a blank line between two consecutive inputs. The first line of the input file contains the size of the lists n (this value can be as large as 4000). We then have n lines containing four integer values (with absolute value as large as 228 ) that belong respectively to A, B, C and D. ===== Output ===== For each testcase you should output exactly one line containing the number of possibilities. This means your output should not contain any spaces and exactly T newline characters. ===== Sample Input ===== 2 1 1 2 3 4 6 -45 22 42 -16 -41 -27 56 30 -36 53 -37 77 -36 30 -75 -46 26 -38 -10 62 -32 -54 -6 45 ===== Sample Output ===== 0 5 Sample Explanation: The sum of the five following quadruplets is zero: (-45, -27, 42, 30), (26, 30, -10, -46), (-32, 22, 56, -46),(-32, 30, -75, 77), (-32, -54, 56, 30).