#include<iostream>
#include<cmath>
#include<cstdlib>

using namespace std;

int main()
{
double pi;
double r;
double per,area;
cout << "請輸入圓半徑：";
cin >> r;
pi = 3.14159;
per = 2*pi*r;
area = r*r*pi;
cout << "圓周長：" << per << endl << "圓面積：" << area;

system("pause");
return 0;
}