。
You've really got me stumped.
Literal
Truly humbly-came-[polite] [agreement-ね].
参りました, literally the humble (謙譲語/kenjougo) past of 参る ('to come / to go'), is used idiomatically as 'I give up,' 'I'm beaten,' or 'I'm at a loss' — the speaker metaphorically humbles themselves in defeat. The polite ~ました keeps the expression socially appropriate, and final ね softens and invites acknowledgment from the listener. A very common set phrase.