#include <iostream>
#include <math.h>
using namespace std;

class triangle
{
public:
    int a, b, c, p, P;
    float S;

    void per()
    {
        P = a + b + c;
        cout << "P = " << P << endl;
        p = P / 2;
    }

    void square()

    {
        S = sqrt(p * (p - a) * (p - b) * (p - c));
        cout << "S = " << S;
    }
};

int main()
{
    triangle today;
    cin >> today.a;
    cin >> today.b;
    cin >> today.c;
    today.per();
    today.square();

    return 0;
}