Draw activity diagram for a gym membership system. When members join the gym, they pay a fee for a certain length of time. Most memberships are for one year, but memberships as short as two months are available. Throughout the year, the gym offers a variety of discounts on their regular membership prices (e.g., two membership for the price of one for Valentine's day). It is common for members to pay different amounts for the same length of membership. The gym wants to mail out reminder letters to members asking them to renew their memberships one month before their memberships expire. Some members have become angry when asked to renew at a much higher rate than their original membership contract, so the club wants to track the prices paid so that the manager can override the regular prices with special prices when members are asked to renew. The system must track these new prices so that renewals can be processed accurately. One of the problems in the industry is the high turnover rate of members. Although some members remain active for many years, about half of the members do not renew their memberships. This is a major problem, because the gym spends a lot in advertising to attract each new member. The manager wants the system to track each time a member comes into the gym. The system will then identify the heavy users and generate a report so the manager can ask them to renew their memberships early, perhaps offering them a reduced rate for early renewal. Likewise, the system should identify members who have not visited the gym in more than a month, so the manager can call them and attempt to re-interest them in the gym.