Hydrogen has two stable isotopes, 11H and 21H, and sulfur has four stable isotopes, 3216S, 3316S, 3416S,

Question:

Hydrogen has two stable isotopes, 11H and 21H, and sulfur has four stable isotopes, 3216S, 3316S, 3416S, and 3616S. How many peaks would you observe in the mass spectrum of the positive ion of hydrogen sulfide, H2S1? Assume no decomposition of the ion into smaller fragments.