// 一个循环搞定
void (async function () {
    const str = await readline();
    let tep = "", count = 0, res = ""
    for (const char of str) {
        if (tep != char) {
            if (tep != "") {
                res += `${count}${tep}`;
            }
            count = 1;
        } else {
            count++;
        }
        tep = char;
    }
    res += `${count}${tep}`
    console.log(res)
})();