An initial mixture of nitrogen gas and hydrogen gas is reacted in a rigid container at a certain temperature by the reaction

3H2(g) +N2(g) <=> 2NH3(g)
At equilibrium the concentrations are [H2]=5.0 M, [N2]= 8.0M, [NH3]=3.0M
What were the concentrations of nitrogen gas and hydrogen gas that were reacted initially.