Solve the following Sudoku puzzle,
$$
\begin{array}{|c|c|c||c|c|c||c|c|c||}
& & & & & & & & \\
\hline 7 & & & 1 & 5 & 4 & & & 8 \\
\hline 2 & & 5 & 9 & & 8 & 1 & & 6 \\
\hline & & 6 & 7 & & 3 & 4 & & \\
\hline & 3 & & & & & & 2 & \\
\hline & & 7 & 2 & & 9 & 6 & & \\
\hline & & 7 & 2 & & 9 & 6 & & \\
\hline 8 & & 3 & 4 & & 2 & 9 & & 5 \\
\hline 5 & & & 8 & 7 & 6 & & & 2
\end{array}
$$