Multithreading: Concurrency.

Consider the following code runs in a multi$-$threaded environment:

uint$64\_$t counter;

void incrementVariable$()$

$\{$

counter$++$;

$\}$

If the initial value of counter was $100,$ what are the possible values of counter after calling incrementVariable$()$ from $2$ different threads? Each of the two threads calls the function exactly one time.