A cruise company operates three ships $A,B,C$ continually on cruises from Florida to the Bahamas

for $7,13$ and $29$ day cruises, respectively. The company needs to hire extra hands on days when

all three ships dock in Florida simultaneously. If these ships left Florida on Monday, Tuesday,

and Wednesday of this week, respectively, find all of the future times when they will be in Florida

simultaneously. What would you suggest to the company if they do not want any two of the ships

to be in Florida on the same day?