Name the type of rhyme scheme used in the following poem.
"O Time, thou must untangle this, not I;
It is too hard a knot for me t' untie!"
The rhyme scheme used in the poem is a rhyming couplet, or "AA."
Complete the following task based on the instruction and optional input provided.### Instruction:
Name the type of rhyme scheme used in the following poem.

### Input:
"O Time, thou must untangle this, not I;
It is too hard a knot for me t' untie!"

### Output:
The rhyme scheme used in the poem is a rhyming couplet, or "AA."