Count Unique Phone Calls

You are given multiple datasets representing call logs. Each dataset starts with an integer n ($1 \le n \le 1000$) which indicates the number of phone numbers in that dataset. This is followed by n lines each containing a phone number (as a string). The datasets are terminated by a single line that contains the number 0.

Your task is to count the number of unique phone numbers in each dataset and output the counts, each on a new line.

Input Format: The input is provided on stdin.

Output Format: For each dataset, output the count of unique phone numbers on a separate line to stdout.

inputFormat

The input consists of several datasets. Each dataset is defined as follows:

• The first line contains an integer n where $1 \le n \le 1000$. If this number is 0, it signals the end of input and should not be processed.
• The next n lines each contain one phone number (a string that may include digits and other characters like '-').

All input is given via stdin.

outputFormat

For each dataset processed, print a single line containing one integer which is the count of unique phone numbers in that dataset. All output should be written to stdout.

## sample

4
123-456-7890
987-654-3210
123-456-7890
345-678-9012
5
1234567890
1234567890
000-000-0000
555-555-5555
555-555-5555
0

3
3

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