[Python] Transform list of dictionaries into nested dictionary

I have the following list of dictionaries

l = [{'u': 1, 'v': 2, 'k': [1, 1, 1, 1, 1]},
{'u': 1, 'v': 3, 'k': [2, 2, 2, 2, 2]},
{'u': 2, 'v': 3, 'k': [3, 3, 3, 3, 3]},
{'u': 1, 'v': 4, 'k': [4, 4, 4, 4, 4]},
{'u': 2, 'v': 5, 'k': [5, 5, 5, 5, 5]}]


I want to created a nested dictionary of this:

nested_d = {
'1': {'2': [1, 1, 1, 1, 1],
'3': [2, 2, 2, 2, 2],
'4': [4, 4, 4, 4, 4]},
'2': {'3': [3, 3, 3, 3, 3],
'5': [5, 5, 5, 5, 5]}
}


How can I achieve this easily (without a for loop / in a one-liner)?

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