function solve() {

    let threeHave = false;

    let theBonusCourse = false;

    let onlineDiscount = false;

    let totalPrice = 0;

    let array = [];

    const theUl = document.querySelector("#myCourses > div.courseBody > ul");

    let ObjectPrices = {
        'js-fundamentals': 170,
        'js-advanced': 180,
        'js-applications': 190,
        'js-web': 490
    }

    let ObjectNames = {
        'js-fundamentals': 'JS Fundamentals',
        'js-advanced': 'JS Advanced',
        'js-applications': 'JS Applications',
        'js-web': 'JS Web'
    }

    let result = document.querySelector("#myCourses > div.courseFoot > p");

    const btnSighnMeUp = document.querySelector("#availableCourses > div.courseFoot > button");

    const bottons = Array.from(document.getElementsByTagName('INPUT'));

    bottons.forEach(bottons => bottons.addEventListener('click', start));

    function start(event) {

        const btn = event.target;

        const status = document.querySelector("#educationForm > input[type=radio]:checked").value;

        if (status === 'online') {

            onlineDiscount = true
        }

        array.push(btn.value);

    }

    btnSighnMeUp.addEventListener('click', end);

    function end() {

        if (array.includes('js-advanced') && array.includes('js-fundamentals')) {

            ObjectPrices['js-advanced'] = 162;
        }

        if (array.includes('js-advanced') && array.includes('js-fundamentals') && array.includes('js-applications')) {

            threeHave = true;

            totalPrice -= 32.4

        }

        if (array.includes('js-advanced') && array.includes('js-fundamentals') && array.includes('js-applications') && array.includes('js-web')) {

            theBonusCourse = true;

        }

        for (let i = 0; i < array.length; i++) {

            if (array[i] !== "online" && array[i] !== "onsite") {

                totalPrice += ObjectPrices[array[i]];
            }

        }

        if (onlineDiscount === true) {
            totalPrice *= 0.94;
        }

        totalPrice = Math.floor(totalPrice) + '.00';

        result.innerHTML = `Cost: ${totalPrice} BGN`;

        for (let k = 0; k < array.length; k++) {

            if (array[k] !== "online" && array[k] !== "onsite") {
                let node = document.createElement("LI");
                let a = ObjectNames[array[k]];
                var textnode = document.createTextNode(a);
                node.appendChild(textnode);
                theUl.appendChild(node);
            }

        }

    }

}
solve();