#include <iostream>
#include <cmath>

using namespace std;

int main() {
    double x,phi , y, k;
    int choice;
    do {
        phi = 0;
        k = 0;
        cout << "Input x:\n";
        cin >> x;
        cout << "Input y:\n";
        cin >> y;
        cout << "Input choice:";
        cout << " 1 - 2x, 2 - x^2, 3 - x/3\n " << endl;
        cin >> choice;
        if (!cin) { cout << "Error type"; return -1; }
        switch (choice)
        {
        case 1:
            phi = 2 * x;
            cout << "phi(x) = 2x";

            break;
        case 2:
            phi = pow(x, 2);
            cout << "phi(x) = x^2";

            break;
        case 3:
            phi = x / 3;
            cout << "phi(x) = x/3";

            break;
        default:
            cout << "Error!!!Wrong input!";

            return 0;
            break;
        }
        if (fabs(x * y) > 10) {
            k = log(fabs(phi) + fabs(y));
            cout << "k = log(fabs(phi) + fabs(y)";
        }
        else if (fabs(x * y) < 10)
        {
            k = exp(phi + y);
            cout << "k = exp(phi + y";
        }
        else
        {
            k = pow(fabs(phi), 2) + y;
            cout << "k = pow(fabs(phi), 2) + y";
        }
        cout << "\nResult = " << k << endl;
    } while (0);

    return 0;
}