Consider the following randomized algorithm ALG for the Time Series

Search problem: Pick j in $\{0,...,$ log $\backslash$phi $\}$ uniformly at random. Trade all savings on the first day i such that the exchange rate pi satisfies pi $>=(2^$j$)$L$.$ If no such exchange rate is encountered, trade all savings on the last day.

Prove that oblivious competitive ratio $\backslash$rho OBL$($ALG$)<=2($log $\backslash$phi $+1).$