输入：num = "1432219", k = 3
"(2) Provide a developer who has requested a signal with respect to a particular user with a digital signal via a reasonably consistent real-time application programming interface that identifies, at a minimum, which of the following categories pertains to the user."
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The objects have been taken to Cardiff University's lab. Conservator Nicola Emmerson is painstakingly removing the dirt of the dig from an ornate copper brooch.
"This would have been a very decorative brooch. I think it's a very special find for the site."