text: function solve(arr) {
  
      let users = {};
  
      for (const input of arr) {
  
          let [cmd, name, text] = input.split('->');
  
  
          if (cmd === 'Statistics') {
              break;
          }
          if (cmd === 'Add') {
  
              if (!users[name]) {
                  users[name] = [];
              } else {
                  console.log(`${name} is already registered`);
  
              }
  
          }
          if (cmd === 'Send') {
  
              users[name].push(text);
  
          }
          if (cmd === 'Delete') {
              if (users[name]) {
                  delete users[name];
              } else {
                  console.log(`${name} not found!`);
  
              }
  
          }
  
      }
  
      let count = Object.keys(users);
  
      console.log(`Users count: ${count.length}`);
  
  
      let entries = Object.entries(users).sort((a, b) => b[1].length - a[1].length);
  
      for (const [name, msg] of entries) {
  
          console.log(name);
          for (const input of msg) {
              console.log(` - ${input}`);
  
          }
  
      }
  
  }
  
  solve([
      'Add->Mike',
      'Add->George',
      'Send->George->Hello World',
      'Send->George->Some random test mail',
      'Send->Mike->Hello, do you want to meet up tomorrow?',
      'Send->George->It would be a pleasure',
      'Send->Mike->Another random test mail',
      'Statistics'
  ]);