text: function solve(arr) {
      let result = arr.reduce((acc, element, index) => {
          if (element === 'add') {
              acc.push(index + 1);
          } else if (element === 'remove') {
              acc.pop();
          }
  
          return acc;
      }, []);
  
      if (result.length > 0) {
          console.log(result.join('\n'));
      } else {
          console.log('Empty');
      }
  }