Consider the following data table named Student.

Student Name        Number  Sex  
Nina                3412    F 
Mike                1234    M  
Nelson              2341    F  

Here is another data table named Teaching Assistants

Subject     ID
Physics     3412
Chemistry   1111
Mathematics 2341  

What is the count of rows returned in the following join operation?
Student _{⊳⊲(Number=ID)} Teaching Assistants

Only enter a single integer. Do not include any extra spaces or newlines.