Hello! Sorry for my language. I have not found in C++ (Microsoft Visual Studio 2008) function for digit Pi, and input it self - "float Pi=3.1415926" and i recived WA in test 3, but when i use Pi=3.141_!6!_926 (It's wrong!) I got Accepted! What you think about this?

you can use acos(-1.0)

you can find const M_PI in <math.h>

M_PI is not defined under Ansi C or the judge.

if you write

#define _USE_MATH_DEFINES
#include <math.h>

then you can use M_PI