Depth of a list X62244

The depth of a list $t$ is the maximum number of nestings of lists that it contains. For example, the depth of $[a, b, c]$ is 1, the depth of $[a, [b, c], d]$ is 2, and the depth of $[[[a]]]$ is 3. The depth of $[]$ is defined to be 0.

Write a program that prints the depth of every given list.

Define and use a recursive function

depth(t)

that returns the depth of a list $t$.

Hint

Using the @ast@ package, you can extract the list $t$ encoded in a string $s$ with @t = ast.literal_eval(s)@.

Input

The input consists of several lists.

Output

Print the depth of every given list.