Alex has recently decided to learn about how to design compilers. As a first step he needs to find the number of different variables that are present in the given code.

So Alex will be provided N statements each of which will be terminated by a semicolon(;). Now Alex needs to find the number of different variable names that are being present in the given statement. Any string which is present before the assignment operator denotes to a variable name.

Input Format: :

The first line contains a single integer N.

Each of the next N lines contains a single statement.

It is guaranteed that all the given statements shall be provided in a valid manner according to the format specified.

Output Format: :

Print the number of different variable name that are present in the given statements.

Constraints: :

\( 1 \le N \le 10^5 \)

\( 1 \le |Statement| \le 100\)