States:

S$0($Initial$)$: The initial state where the $\text{'}$go$\text{'}$ flag is not set and 'done' flag is false.S$1($Go$)$: The state where $\text{'}$go$\text{'}$ flag is set.S$2($Compare$)$: The state where $\text{'}$m$\text{'}$ and $\text{'}$n$\text{'}$ are compared to check if they are equal.S$3($M $>$ N$)$: The state where $\text{'}$m$\text{'}$ is greater than $\text{'}$n$\text{'}.$S$4($M $<$ N$)$: The state where $\text{'}$m$\text{'}$ is less than $\text{'}$n$\text{'}.$S$5($GCD$)$: The state where the GCD is calculated and 'done' flag is set to true.

Transitions:

S$0$ to S$1$: When the $\text{'}$go$\text{'}$ flag becomes true.S$1$ to S$2$: When $\text{'}$go$\text{'}$ flag is true and 'done' flag is false.S$2$ to S$3$: When $\text{'}$m$\text{'}$ is greater than $\text{'}$n$\text{'}.$S$2$ to S$4$: When $\text{'}$m$\text{'}$ is less than $\text{'}$n$\text{'}.$S$3$ to S$2$: When $\text{'}$m$\text{'}$ is greater than $\text{'}$n$\text{'}$ and 'done' flag is false.S$4$ to S$2$: When $\text{'}$m$\text{'}$ is less than $\text{'}$n$\text{'}$ and 'done' flag is false.S$2$ to S$5$: When $\text{'}$m$\text{'}$ is equal to $\text{'}$n$\text{'}.$