I1.3 If $R$ is the unit digit of the value of $8^{Q}+7^{10 Q}+6^{100 Q}+5^{1000 Q}$, find the value of $R$.
$\begin{array}{l}8^{36} \equiv 6(\bmod 10), 7^{360} \equiv 1(\bmod 10), 6^{360} \equiv 6(\bmod 10), 5^{36000} \equiv 5(\bmod 10) \\ 8^{36}+7^{360}+6^{3600}+5^{36000} \equiv 6+1+6+5 \equiv 8(\bmod 10) \\ R=8\end{array}$