Chemistry : Balancing Chemical Equations

What numbers are needed in the blanks to balance the following chemical equations?
Type these numbers separated by commas with no spaces in the answer.
Example :
Word Equation : Sulfur + Sulfuric acid → Sulfur dioxide + Water
Molecular Equation : _______ S + _______ H₂SO₄ → _______ SO₂ + _______ H₂O
Balanced Equation : S + 2 H₂SO₄ → 3 SO₂ + 2 H₂O
Answer : 1,2,3,2