SP1296 SUMFOUR - 4 values whose sum is 0

The SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how many quadruplet (a, b, c, d ) belongs to A x B x C x D are such that a + b + c + d = 0 . In the following, we assume that all lists have the same size n

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 2 $ ^{28} $ ) that belong respectively to A, B, C and D . (**Edited:** n

Output should be printed on a single line.