1. Meanings
   1. Low competition - low search volume <999 per month
   2. Medium competition - medium search volume 1000-3000 per month
   3. High competition - high search volume 3000-... per month
   4. Medium competition - low search volume
2. berlin travel
   1. berlin travel rick steves
   2. berlin travel blog
   3. berlin vacation
      1. berlin vacation guide
         1. travel guide berlin hotels
         2. free tour guide berlin
         3. dangers berlin
         4. berlin vacation intinerery
         5. vacation rental berlin
         6. indie travel guide berlin
         7. restaurant guide berlin
      2. berlin planning guide
      3. berlin vacation packages
         1. travel deals berlin vacation packages
         2. berlin cheap deals
         3. review hotels berlin
         4. berlin package deals
         5. flight hotel deals berlin
      4. berlin vacation rentals
         1. rent boat berlin
         2. rent apartment berlin
3. berlin hostel
   1. Subtopic 1
   2. Subtopic 2
   3. Subtopic 3
4. berlin hotel deals
   1. Subtopic 1
   2. Subtopic 2
   3. Subtopic 3
5. berlin airport hotel
   1. Subtopic 1
   2. Subtopic 2
   3. Subtopic 3
6. berlin hotel ohio
   1. Subtopic 1
   2. Subtopic 2
   3. Subtopic 3