How many months after the February Revolution of 1917 did the Ossetians set up a National Council of Ossetians which convened in Java ?
return the  February Revolution of 1917 ;return the  Ossetians  set up a National Council of Ossetians which convened in  Java ;return month of #1 ;return month of #2 ;return the  difference of #4 and  #3
['select', 'select', 'project', 'project', 'arithmetic']