Wash chicken giblets and remove the films. Place in a pan with water and quickly bring to the boil. Skim off the foam, salt, slack the fire and cook for 10 minutes. Remove giblets from the broth and rinse with warm water. Strain out the broth. Chop giblets into small pieces and put back into the broth. Bring to the boil once again. While giblets are boiling, prepare vegetables. Peel carrots, celery and onion, cut into thin strips and fry in a preheated vegetable oil for 4 minutes. Add the vegetables to the saucepan with broth and cook for 10 minutes. Meanwhile, pare cucumbers, put in a saucepan, pour 1 cup boiling water and cook for 10 minutes. Strain out the broth. Cut cucumbers into strips, put them in a broth and pour in the cucumber brine. Bring to the boil and remove from fire. Peel potatoes, cut into strips and add to the soup. Boil for 5 minutes. Rinse rice with warm water and add to the soup, cook for 7 minutes. Add cucumbers together with the broth, bay leaves and peppercorn. Salt to taste and cook for 10 minutes. Remove from fire and divide between bowls. Serve with sour cream.