question: How many volunteers were from Sofia, Tirnovo, Troyan, Pleven, Orhanye, and Pazardzhik combined?
#1 return volunteers 
#2 return #1 from  Sofia 
#3 return #1 from  Tirnovo 
#4 return #1 from  Pleven 
#5 return #1 from  Orhanye 
#6 return #1 from  Pazardzhik 
#7 return #1 from  Troyan 
#8 return number of  #2 
#9 return number of  #3 
#10 return number of  #4 
#11 return number of  #5 
#12 return number of  #6 
#13 return number of  #7 
#14 return sum of #8 ,    #9 ,  #10 ,   #11 ,     #12 , #13