Score : 100 points
In this problem, you should process T testcases.
For each testcase, you are given four integers N, M, A, B.
Calculate \sum_{i = 0}^{N - 1} floor((A \times i + B) / M).
Input is given from Standard Input in the following format:
T N_0 M_0 A_0 B_0 N_1 M_1 A_1 B_1 : N_{T - 1} M_{T - 1} A_{T - 1} B_{T - 1}
Print the answer for each testcase.
5 4 10 6 3 6 5 4 3 1 1 0 0 31415 92653 58979 32384 1000000000 1000000000 999999999 999999999
3 13 0 314095480 499999999500000000