Table: Ads

+-------------+------+
| Column Name | Type |
+-------------+------+
| ad_id       | int  |
| customer_id | int  |
| timestamp   | int  |
+-------------+------+
ad_id is the column with unique values for this table.
customer_id is the ID of the customer viewing this ad.
timestamp is the moment of time at which the ad was shown.

Write a solution to report all the sessions that did not get shown any ads.

Return the result table in any order.

The result format is in the following example.

Examples

Example 1

Related Tags