Count Distinct Artifacts

You are given a sequence of artifacts represented by a string S. Each artifact is represented by a character. Your task is to count the number of distinct artifacts in the sequence.

Formally, given a string \(S\) of length \(n\), compute the number of distinct characters contained in \(S\). For example, if \(S = \texttt{abca}\), then the answer is 3 because the distinct artifacts are \(\{a, b, c\}\).

inputFormat

The input consists of a single line containing a non-empty string \(S\) representing the sequence of artifacts.

You can assume that \(S\) contains only ASCII characters without any spaces.

outputFormat

Output a single integer representing the number of distinct artifacts in \(S\).

abca

3