code: function getSlavicForm (c) {
      if (Math.floor(c) !== c) {
        return 2
      } else if ((c % 100 >= 5 && c % 100 <= 20) || (c % 10 >= 5 && c % 10 <= 9) || c % 10 === 0) {
        return 0
      } else if (c % 10 === 1) {
        return 1
      } else if (c > 1) {
        return 2
      } else {
        return 0
      }
    }
docs: Internal helper function for Russian and Ukranian languages.