PROGRAMMING:Most letters
Input a string composed of lowercase English letters, count the most frequent letters and the number of occurrences, and output.
###Input format:
Enter a string of lowercase letters.
###Output format:
Output the most frequent letters and the number of occurrences, separated by commas, and finally wrapped.
###Input example:
```in
abcdefghijklmnopqrstuvwxyzmmm
```
###Output example:
```out
m,4
```
answer：If there is no answer, please comment
###Input format:
Enter a string of lowercase letters.
###Output format:
Output the most frequent letters and the number of occurrences, separated by commas, and finally wrapped.
###Input example:
```in
abcdefghijklmnopqrstuvwxyzmmm
```
###Output example:
```out
m,4
```
answer：If there is no answer, please comment