L. Spin To Win
time limit per test
0.5 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output
Examples
Input
3
0 0
0 1
0 10
Output
4.500000
Input
5
0 0
-3 0
-2 2
-1 3
0 4
Output
1.414214
Input
5
-3 -8
-8 -4
-4 -4
8 3
6 0
Output
5.385165