#include <iostream>
using namespace std;

int main(int argc, char* argv[]) {
    // You can ignore the next few lines
    if (argc != 5) {
        cout << "You must enter 4 values after the program name\n";
        exit(1);
    }
    double a = atof(argv[1]);
    double b = atof(argv[2]);
    double c = atof(argv[3]);
    double d = atof(argv[4]);
    cout << "a = " << a << ", b = " << b << ", c = " << c
         << ", d = " << d << endl;

    // Make changes after this line
    double expr1 = 0; // change this line for expression 1
    cout << "Expression 1: " << expr1 << endl; // do not change this line

    double expr2 = 0; // change this line for expression 2
    cout << "Expression 2: " << expr2 << endl; // do not change this line

    double expr3 = 0; // change this line for expression 3
    cout << "Expression 3: " << expr3 << endl; // do not change this line

    double expr4 = 0; // change this line for expression 4
    cout << "Expression 4: " << expr4 << endl; // do not change this line

    double expr5 = 0; // change this line for expression 5
    cout << "Expression 5: " << expr5 << endl; // do not change this line

    // Add extra credit after this line
}