A traffic signal cycles from $\text{ GREEN to YELLOW, YELLOW to RED and RED to GREEN.}$ In each cycle, $\text{GREEN}$ is turned on for $70$ seconds,$\text{YELLOW}$ is turned on for $5$ seconds and the $\text{RED}$ is turned on $75$ seconds. This traffic light has to be implemented using a finite state machine $\text{(FSM)}$. The only input to this $\text{FSM}$ is a clock of $5$ second period. The minimum number of flip-flops required to implement this $\text{FSM}$ is _________.