// //Города и страны
fetch('https://raw.githubusercontent.com/russ666/all-countries-and-cities-json/master/countries.json')
    .then(res => res.json())
    .then(json => {
        let countrySelect = document.querySelector('select');
        let citySelect = document.createElement('select');

        for(let countryChoice in json) {
            let countrySelectOption = document.createElement('option');
            countrySelectOption.innerText = countryChoice;
            countrySelect.append(countrySelectOption);
        }

        countrySelect.onchange = () => {
            let cityChoice = json[countrySelect.value];
            citySelect.innerHTML = '';

            for (let key in cityChoice) {
                let citySelectOption = document.createElement('option');
                citySelectOption.innerText = cityChoice[key];
                citySelect.append(citySelectOption);
            }
        }

        document.body.append(countrySelect);
        document.body.append(citySelect);
    })

// Таблица умножения
let table = document.createElement('table');
let caption = document.createElement('caption');

for (let i = 0; i <= 9; i++) {
    let row = document.createElement('tr');

    for (let j = 0; j <= 9; j++) { 
        let col = document.createElement('td');
        col.onmouseover = function() {
            row.style.background = '#00BFFF';
            col.style.background = '#FFDAB9';
            
            for(let i = 0; i <= 9; i++) {
                table.children[i].children[j].style.background = '#FFDAB9';
            }
        }

        col.onmouseout = function() {  
            row.style.background = '';
            col.style.background = '';
            for(let i = 0; i < table.children.length; i++) {
                table.children[i].children[j].style.background = '';
            }
        }

        caption.onmouseover = function() {
            caption.style.background = '#00BFFF';
            caption.style.color = '#FFF';
        }

        caption.onmouseout = function() {
            caption.style.background = '';
            caption.style.color = '';
        }
        
        let val = i * j;
        if (val === 0) {
            val = i || j;
        }

        col.innerHTML = val;
        row.appendChild(col);
        table.appendChild(row);
    }

    if (caption) {
        table.appendChild(caption);
    }  
}

document.body.appendChild(table);