#include <iostream>
int main()
{
int r = 0;
double P;
const double PI = 3.141592653589793;
double S;
std::cout << "Enter r:";
std::cin >> r;
std::cout << std::endl;
P = 2 * PI * r;
S = PI * (r * r);
std::cout << "P = " << P << std::endl;
std::cout << "S = " << S;
}
#include <iostream>
int main()
{
int r = 0;
double P;
const double PI = 3.141592653589793;
double S;
std::cout << "Enter r:";
std::cin >> r;
std::cout << std::endl;
P = 2 * PI * r;
S = PI * (r * r);
std::cout << "P = " << P << std::endl;
std::cout << "S = " << S;
}