The function $f$ is given by the table  
$$\begin{array}{|c||c|c|c|c|c|}\hline\text{x}&1&2&3&4&5\\\hline\text{f(x)}&4&1&3&5&2\\\hline\end{array}$$  
If $u_0=4$ and $u_{n+1} = f(u_n)$ for $n \ge 0$, find the value of $u_{2002}$.

Let's think step by step and output the final answer within \boxed{}.
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