Let
\[
P =
\begin{pmatrix}
0 & 1 & 1 & 1 & 1 \\
-1 & 0 & 1 & 1 & 1 \\
-1 & -1 & 0 & 1 & 1 \\
-1 & -1 & -1 & 0 & 1 \\
-1 & -1 & -1 & -1 & 0
\end{pmatrix}
\]
If \( \lambda_1, \lambda_2, \lambda_3, \lambda_4, \lambda_5 \) are eigenvalues of \( P \), then \( \prod_{i=1}^{5} \lambda_i = \) ________ (answer in integer).