So what should be kept for this input?

%input=(
    r=>[1,2],
    s=>[2,3],
    t=>[1,3]
);
[download]

Also, please show us the code you have already written, and the input data, and your output, and please also explain how the output is not what you want.

Update: Also, please do not repost your questions if you've already got answers. Please include a reference to your previous questions and also explain what problems you have with the previous answers. I consider it very rude to not mention that you already asked your question before.

Eliminate Array of array duplication

Sub array in Array of array