Two functions are defined mutually: E(n)={0if n=0O(n−1)+1if n>0E(n) = \begin{cases} 0 & \text{if } n = 0 \\ O(n-1) + 1 & \text{if } n > 0 \end{cases}E(n)={0O(n−1)+1if n=0if n>0 and O(n)={0if n=0E(n−1)+1if n>0O(n) = \begin{cases} 0 & \text{if } n = 0 \\ E(n-1) + 1 & \text{if } n > 0 \end{cases}O(n)={0E(n−1)+1if n=0if n>0. Find O(5)O(5)O(5).
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