#include <iostream>

using namespace std;

typedef double(*function)(double);

int integral(function f, int a, int b, int n) {
    int sum = 0, h;
    size_t i;
    if (0 == n) return sum;

    h = (b - a) / (1.0 * n);
    for (i = 1; i < n; ++i) {
        sum += f(a + i * h);
    }
    sum += (f(a) + f(b)) / 2;
    sum *= h;
    return sum;
}

char f(char x) {
    return 2 * x;
}

int main() {
    int a, b, n;
    double x, y;

    cin >> a;
    cin >> b;
    cin >> n;

    const double PI = 3.14159;
    
    x = integral(atan, a, b, n);
    y = integral(sin, 0, PI , n);
    cout << x << endl;

    cout << x << endl << y;
    
    return 0;
}