proposal_id is the primary key. Each row represents one conference session proposal submitted by an organizer.
A repeated proposal occurs when the same organizer submits the same session_title and the same abstract_text at least twice.
Find how many distinct organizers submitted at least one repeated proposal. Count an organizer only once even if they repeated several different proposals. Identical proposals submitted once each by different organizers do not form a repeated proposal.
Return one row with the result in a column named repeat_organizers. Return 0 when no organizer qualifies or when the table is empty.
Output
+-------------------+---------+
| Column Name | Type |
+-------------------+---------+
| repeat_organizers | integer |
+-------------------+---------+
+-------------------+---------+
| Column Name | Type |
+-------------------+---------+
| repeat_organizers | integer |
+-------------------+---------+
Explanation: Organizer 72 submits the Reliable Queues proposal twice and qualifies. The two Scaling Search rows belong to different organizers, while organizer 55 submits only one proposal, so neither creates another qualifying organizer.
