Observe the following reactions (unbalanced)

$ \begin{array}{r} \mathrm{P}_{2} \mathrm{O}_{3}+\mathrm{H}_{2} \mathrm{O} \longrightarrow X \\ \mathrm{P}_{4} \mathrm{O}_{10}+\mathrm{H}_{2} \mathrm{O} \longrightarrow Y \end{array} $

The number of $\mathrm{P}=\mathrm{O}$ bonds present in $X, Y$ are respectively

Observe the following species.

(i) $\mathrm{NH}_3$

(ii) $\mathrm{AlCl}_3$

(iii) $\mathrm{SnCl}_4$

(iv) $\mathrm{CO}_2$

(v) $\mathrm{Ag}^{+}$

(vi) $ \mathrm{HSO}_{4}^{-} $

How many of the above species act as Lewis acids?