A 2.52-g sample of a compound containing only carbon, hydrogen, nitrogen, oxygen, and sulfur was burned in excess oxygen to yield 4.23 g of CO2 and 1.01 g of H2O. Another sample of the same compound, of mass 4.14 g, yielded 2.11 g of SO3. A third sample, of mass 5.66 g, was burned under different conditions to yield 2.27 g of HNO3 as the only nitrogen containing product. Calculate the empirical formula of the compound.