function solve() {
    let selectMenuToElement = document.querySelector('#selectMenuTo');
    let inputElement = document.querySelector('#input');
    let outputElement = document.querySelector('#result');
    let toElement = document.querySelector('#selectMenuTo option');

    toElement.value = 2;
    toElement.textContent = 'Binary';

    let toElementCln = toElement.cloneNode(true);
    toElementCln.value = 16;
    toElementCln.textContent = 'Hexadeicmal';

    selectMenuToElement.appendChild(toElementCln);

    let buttonElement = document.querySelector('button');

    buttonElement.addEventListener('click', function() {

        let number = Number(inputElement.value);
        let toStringValue = Number(document.querySelector('#selectMenuTo').value);

        outputElement.value = ((number).toString(toStringValue)).toUpperCase();

        inputElement.value = '';
    })
}