#include <iostream>

const double PI = 3.14;

double area(double r1, double l1) {
    return PI * r1 * (l1 + r1);
}

int main() {
    double r = 0, l = 0;

    std::cout << "Input a number for r: ";
    std::cin >> r;

    std::cout << "Input a number for r: ";
    std::cin >> l;

    std::cout << "The result of [K for r = " << r << ", l = " << l << "] is: " << area(r, l) << std::endl;
    std::cout << "The result of [K=area(r, l) - 5] is: " << area(r, l) - 5 << std::endl;
    std::cout << "The result of [K for r = 2, l = 3] is: " << area(2, 3) << std::endl;

    return 0;
}