If $A$ and $B$ are two finite sets such that $n\left[\mathrm{P}\right(\mathrm{A}\left)\right]=n\left[\mathrm{P}\right(\mathrm{B}\left)\right]+992, n\left(\mathrm{A}\right)+n\left(\mathrm{B}\right)$ is

Let $A, B \mathrm{and} C$ are three sets such that $n\left(A\right)=6,n\left(B\right)=5,n\left(C\right)=7,n(A\cap B)=3$,$n(\mathrm{B}\cap \mathrm{C})=3,n(\mathrm{A}\cap \mathrm{C})=2\text{ and }n(\mathrm{A}\cap \mathrm{B}\cap \mathrm{C})=1$. Then number of elements in exactly one of these three sets is