Regular polygon

On a two-dimensional plane, give you n integer points. Your task is to figure out how many different regular polygon these points can make.

The input file consists of several test cases. Each case the first line is a numbers N (N <= 500). The next N lines ,each line contain two number Xi and Yi(-100 <= xi,yi <= 100), means the points’ position.(the data assures no two points share the same position.)

For each case, output a number means how many different regular polygon these points can make.

4
0 0
0 1
1 0
1 1
6
0 0
0 1
1 0
1 1
2 0
2 1

1
2

2017 Multi-University Training Contest - Team 2