How do I balance an equation for chemistry P4(s)+Cl2(g) -> PCl5(g)

P4(s)+Cl2(g) -> PCl5(g)
i have to Enter the coefficients in order, separated by commas (e.g., 1,2,3).

I just dont get this. can anyone help me, Please?

balanced equation:
P4 + 10 Cl2 → 4 PCl5

The coefficients are: 1,10,4

Whut