Calculate Average Feedback Score

You are given a series of feedback entries. Each entry is provided on a new line and contains a category name and a feedback score separated by a space. The input terminates with a line containing only "END".

Your task is to compute the average feedback score for each category. The average must be rounded to two decimal places and displayed in the format: CategoryName: average_score. The categories should be output in the order in which they first appear in the input.

For example, if the input is:

Work Quality 8
Initiative 7
Teamwork 9
Work Quality 10
Initiative 9
END

The output should be:

Work Quality: 9.00
Initiative: 8.00
Teamwork: 9.00

Note: If a category appears multiple times, its average is computed over all its scores.

inputFormat

The input is provided via standard input (stdin) and consists of multiple lines. Each line (except the last one) contains a feedback entry in the format:

CategoryName Score

The last line contains the string END, which signifies the end of input.

outputFormat

Output the average feedback score for each category to standard output (stdout). Each line of the output should follow the format:

CategoryName: average_score

where average_score is the average score for that category, rounded to two decimal places. The categories are listed in the order they first appear in the input.

## sample

Work Quality 8
Initiative 7
Teamwork 9
Work Quality 10
Initiative 9
END

Work Quality: 9.00
Initiative: 8.00
Teamwork: 9.00

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