3

#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES

#include<iostream>
#include<algorithm>
#include<vector>
#include<math.h>
#include <cmath>

using namespace std;
#define ll long double

ll x0, xk, h;

int main(void) {
    cin >> x0 >> xk >> h;
    for (ll i = x0; i < xk; i += h) {
        cout << "F(" << i << ") = ";
        if (i < 2)cout << "empty set" << endl;
        else if (i == 2)cout << i * i << " - b^2" << endl;
        else cout << (i - 2 * sin(M_PI*i / 2)) << endl;
    }
    cin >> x0;

}