Help with this word problem please?

weekend of car wash. homeroom reps are signing up volunteer car washers. the first 6 homerooms have 7 vol. each. half of the remaining vol. come from the next 6 homerooms. The next 4 representatives bring in the names of 36 volunteers. The next 2 reps bring in one half of the remaining vol. and the last homeroom brings in the names of 8 vol. How many students volunteer to be car washers? Everyone is stuck on this problem!!