Split 50 mp3 files into 5000 small audio clips

I have 50 mp3 files with 100 sentences in them each which are numbered in the audio. I need the sentence after the number.

There should be at least a 0.2 second gap at the front of the audio clips and not much more than that.

Sometimes a sentences has been recorded more than one time. In this case please use the last sentence recorded.

The audio is in Thai langauge but the numbers are in English so no need to speak Thai for this.

I have attached a sample.

I need the files saved as high quality mp3 256kbps.

Thank you