Compounds Containing Nitrogen

A student has been given a compound " $x$ " of molecular formula- $\mathrm{C}_6 \mathrm{H}_7 \mathrm{~N}$. ' $x$ ' is sparingly soluble in water. However, on addition of dilute mineral acid, ' $x$ ' becomes soluble in water. ' $x$ ' when treated with $\mathrm{CHCl}_3$ and $\mathrm{KOH}(\mathrm{alc})$, ' $y$ ' is produced. ' $y$ ' has a specific unpleasant smell. On treatment with benzenesulphonyl chloride, ' $x$ ' gives a compound ' $z$ ' which is soluble in alkali. The number of different " H " atoms present in ' z ' is:-