I failed to use the do-while or while loop for the following diagram:

Here, A, B, and C are functions.
How can I write pseudocode for the diagram above?
EDIT: This is from my programming practice of C++. Without the “B loop” (or the “A loop”), I am able to write it as the following:
Start
Input x;
while(x!=2)
{
A(); Input x;
}
C();
End
However, when the “B loop” comes in, I have no idea how to include it.
But beware of the langage you are using I advise you to add a sleep mode between data aquisitions (Just before Input x)