first_values AS (
    SELECT DISTINCT(user_id),
           FIRST_VALUE(a.first_date) OVER (PARTITION BY a.user_id ORDER BY a.datetime) AS first_date,
           FIRST_VALUE(c.city_name) OVER (PARTITION BY a.user_id ORDER BY a.datetime) AS first_city,
           FIRST_VALUE(c.city_id) OVER (PARTITION BY a.user_id ORDER BY a.datetime) AS city_id
    FROM analytics_events a
    LEFT JOIN cities c ON a.city_id = c.city_id
    WHERE event = 'authorization'
          AND a.user_id IS NOT NULL
          AND a.log_date <= '2021-07-02'
          AND a.first_date <= '2021-06-26'