function solve(input) {

  function objectCreation(input) {

    let comments = {

      articles: [],

      users: [],

    };

    let pattern = /article \w+|user \w+/g;

    while (input[0] !== undefined) {

      let cur = input.shift();

      if (cur.match(pattern) !== null) {

        cur = cur.split(' ');

        if (cur[0] === 'article') {

          comments.articles.push(cur[1]);

        } else if (cur[0] === 'user') {

          comments.users.push(cur[1]);

        }

      } else {

        cur = cur.split(/\sposts\son\s|:\s/g);

        // console.log(cur);

        if (comments.articles.includes(cur[1]) && comments.users.includes(cur[0])) {

          if (comments.hasOwnProperty(cur[1])) {

            comments[cur[1]][cur[0]] = cur[2];

          } else {

            comments[cur[1]] = { [cur[0]]: cur[2] };

          }

        }

      }

    }

    delete comments.articles;

    delete comments.users;

    return comments;

  }


  function arrayCreation() {

    let comments = objectCreation(input);

    let arr = [];

    for (let art in comments) {

      let arr2 = [];

      for (let key in comments[art]) {

        arr2.push([key, comments[art][key]]);

      }

      arr.push([art, arr2]);

    }

    return arr;

  }


  function sorting() {

    let arr = arrayCreation();

    arr.sort((a, b) => Object.keys(b[1]).length - Object.keys(a[1]).length);

    for (let el of arr) {

      el[1].sort((a, b) => a[0].localeCompare(b[0]));

    }

    return arr;

  }


  function printing() {

    let arr = sorting();

    for (let el of arr) {

      console.log(`Comments on ${el[0]}`);

      for (let el2 of el[1]) {

        let el3 = el2[1].split(', ');

        console.log(`--- From user ${el2[0]}: ${el3[0]} - ${el3[1]}`);

      }

    }

  }

  printing();


}