I1.1 Let $P$ be the unit digit of $3^{2003} \times 5^{2002} \times 7^{2001}$. Find the value of $P$.
I1.2 If the equation $\left(x^{2}-x-1\right)^{x+P-1}=1$ has $Q$ integral solutions, find the value of $Q$.
I1.3 Let $x, y$ be real numbers and $x y=1$.
If the minimum value of $\frac{1}{x^{4}}+\frac{1}{Q y^{4}}$ is $R$, find the value of $R$.
11.4 Let $x_{R}, x_{R+1}, \ldots, x_{K}(K>R)$ be $K-R+1$ distinct positive integers and $x_{R}+x_{R+1}+\ldots+x_{K}=2003$ If $S$ is the maximum possible value of $K$, find the value of $S$. (Reference: 2004 HI4)