What is the sum of the least and the greatest positive four-digit multiples of 4 that can be written each using the digits 1, 2, 3 and 4 exactly once?
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
What is the sum of the least and the greatest positive four-digit multiples of 4 that can be written each using the digits 1, 2, 3 and 4 exactly once?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
5636
What is the sum of the least and the greatest positive four-digit multiples of 4 that can be written each using the digits 1, 2, 3 and 4 exactly once?
train