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