#include <iostream>
#include <cmath>

using namespace std;

int main()
{
    double x;
    cout << "Vvedite x: ";
    cin >> x;

    cout << endl << "f(x) = ";
    if ( x > 5 )
        cout << exp(sin(x) - cos(x)) << endl;
    else if ( x > -3 && x <= 5 )
        cout << 1/(1 -x -6*x*x) << endl;
    else
        cout << acos(8/log(-1.0)) << endl;

    return 0;
}