Total number of geometrical isomers for the complex $\left[\mathrm{RhCl}(\mathrm{CO})\left(\mathrm{PPh}_3\right)\left(\mathrm{NH}_3\right)\right]$ is ___________.

Two aliphatic aldehydes $\mathbf{P}$ and $\mathbf{Q}$ react in the presence of aqueous $\mathrm{K}_2 \mathrm{CO}_3$ to give compound $\mathbf{R}$, which upon treatment with HCN provides compound $\mathbf{S}$. On acidification and heating, $\mathbf{S}$ gives the product shown below :

The compounds P and Q respectively are :

Two aliphatic aldehydes $\mathbf{P}$ and $\mathbf{Q}$ react in the presence of aqueous $\mathrm{K}_2 \mathrm{CO}_3$ to give compound $\mathbf{R}$, which upon treatment with HCN provides compound $\mathbf{S}$. On acidification and heating, $\mathbf{S}$ gives the product shown below :

The compound R is :

Two aliphatic aldehydes $\mathbf{P}$ and $\mathbf{Q}$ react in the presence of aqueous $\mathrm{K}_2 \mathrm{CO}_3$ to give compound $\mathbf{R}$, which upon treatment with HCN provides compound $\mathbf{S}$. On acidification and heating, $\mathbf{S}$ gives the product shown below :

The compound S is :