var autos = {
    car : function(_mileageType) {
        // (1) Add member variables here:
        // ie this.variableName = arg;
        // for storing the mileage and mileageType
        this.mileageType = _mileageType;
        this.f = 0;
        this.r = 0;
        this.forward = function (x) {
            // (2) complete this method for mileage driving forward
            // This method should log the forward mileage (x as an integer) and has no return value
            x > 0 ? f = x : f = 0;
        };
        this.reverse = function (y) {
            // (3) complete this method for mileage driving in reverse
            // This method should log the reverse mileage (y as an integer) and has no return value
            y > 0 ? r = y : r = 0;
        };
        this.getTotalMileage = function() {
            // (4) complete this method for getting the total mileage
            // This method should return the total mileage as an integer
            var miles;
            if (this.mileageType == "net")
                miles = f - r;
            else miles = f + r;
            return miles;
        };
    }
};

// ***Do not modify code below here***
function solution(X, Y, U) {
    // Create a new car object
    var car  = new autos.car(U);
    // Drive forward and reverse
    car.forward(X);
    car.reverse(Y);
    // Return the total mileage driven
    return car.getTotalMileage();
}