Since members of ZSTU ACM Team are lack of exercise, they plan to participate in a ten-thousand-people Marathon. It is common that the athletes run very fast at first but slow down later on. Start from this moment, we can assume that everyone is moving forward in a constant speed. ACMers love algorithms, so they want to know not only the result but also who may be in the leading position. Now we know all athletes’ position and speed at a specific moment. The problem is, starting from this moment, how many athletes may be the leader. Please notice that there’s no leader if two or more athletes are at the leading position at the same time. No two athletes may have the same speed.

The input consists of several test cases. The first line of input consists of an integer T, indicating the number of test cases. The first line of each test case consists of an integer N, indicating the number of athletes. Each of the following N lines consists of two integers: p, v, indicating an athlete’s position and speed. Technical Specification 1. T <= 20 2. 0 < N <= 50000 3. 0 < p, v <= 2000,000,000 4. An athlete’s position is the distant between him/her and the start line. 5. The Marathon is so long that you can assume there’s no finishline.

For each test case, output the number of possible leaders on a separate line.

The 4th Baidu Cup Central China Invitational Programming  Contest (Final Round)