Ordinal Number

Ordinal numbers are an extension of the set of nonnegative integers. For each nonnegative integer $x$, we will establish the corresponding ordinal number $f (x)$. The first few ordinal numbers can be defined as follows.

• Zero corresponds to an empty set: $f(0) = ${}.
• One corresponds to the set containing the set $f (0)$ as an element: $f(1) = ${$f(0)$}$ = ${{}}.
• Two corresponds to the set containing the sets $f (0)$ and $f (1)$ as elements: $f(2) = ${$f(0), f(1)$}$ = ${{},{{}}}.
• And so on: each positive integer $k$ corresponds to the set containing all the previous ordinal numbers as elements. The formula is: $f(k) = ${$f(0), f(1), \ldots , f(k - 1)$}.

Next, we can similarly define ordinal numbers that don't correspond to integers. Alas, we won't need them in this problem.

You are given a string describing an ordinal number corresponding to a nonnegative integer $n$. Find $n$.

The first line contains the description of an ordinal number corresponding to a certain nonnegative integer $n$ ($0 \le n \le 15$). It consists of the characters "{", ",", and "}".

In the description of each set, each element appears exactly once. However, as a set does not change if we change the order of elements, this order can be arbitrary.

Print the integer $n$ corresponding to the given ordinal number.