PROGRAMMING:Count the number of words and the average length of words in the input string (exercise 7-7, fundamentals and applications of Python programming, Higher Education Society)

Write a program to accept a line of English sentences input by the user (assuming that the sentence is only composed of English words and spaces, excluding commas and other symbols), count and output the number of words and the average length of words in the line.
###Input format:
Word 1 word 2... Word n
###Output format:
Number of words, average length of words (two decimal places reserved)
###Input example:
```in
aaa bbb ccccccccccc
```
###Output example:
```out
3,5.67
```







answer：If there is no answer, please comment