How does SHELL read row data that matches the string cyclically Based on the provided string?

How does SHELL read the row data that matches the string cyclically Based on the provided string-Linux general technology-Linux technology and application information? The following is a detailed description. Hello everyone, I want to write a SHELL script to read the row data that matches the string according to the provided string loop, such as FILE1:
100 ROWS
99 no
200 ROWS
99 no
99 no
300 ROWS
How can I cyclically read the numbers in front of the row matched by ROWS and assign them to a variable?

If you still need to use the first word of the row that matches the ROWS string according to the input parameters, you do not need to loop.