求圆周率

FJNU.1720

Description
Output
圆周率的值，精确到小数点后6位(答案之后不用输出回车)

Sample Output
3.141593

My Program

#include < iostream >
using   namespace  std;

int  main()
... {
      cout<<"3.141593";
      return 0;
}

 YOYO's Note: 
直接输出结果勒 = = ||