How many total Serbian troops and volunteers fought the rebel Greens?
return Serbian troops ;return Serbian volunteers ;return #1 that fought the  rebel Greens ;return #2 that fought the  rebel Greens ;return number of  #3 ;return number of  #4 ;return the  sum of #5 and  #6
['select', 'select', 'filter', 'filter', 'aggregate', 'aggregate', 'arithmetic']