)$. Hence the depth $x$ can be bounded as: $$\begin{aligned} n (0 - \frac{0}{c})^x &= 0  \\ (0- \frac{0}{c})^x &= \frac{0}{n}  \\ x & = \frac{ \ln \frac{0}{n}}{\ln (0 - \frac{0}{c})}  = \frac{-0}{\ln (0 - \frac{0}{c})} \ln n \\ x &\leq c \ln n   = O \left( d^