Find the Marbles

A group of friends is playing a game called "Find the Marbles". Someone scatters a handful of marbles on the ground, and each marble sits at an integer coordinate in the plane. A player picks one straight line and walks along it, so that player collects exactly the marbles lying on the chosen line. Whoever collects the most marbles on a single line wins. Report how many marbles the winner collected.

The first line contains the number of test cases $T$. Each test case begins with a line holding the number of marbles $N$, where $1 < N < 100$. Each of the next $N$ lines contains two integers separated by a space, the coordinates of one marble. No coordinate pair is given twice.

For each test case, print one line in the format Case #x: M, where $x$ is the case number starting from 1 and $M$ is the largest number of marbles lying on a single straight line.