Amritapuri tickets?

Can anyone tell me that for ACM icpc onsite round in Amritapuri which is the nearest airport to amritapuri so that I can reach amritapuri easily from lucknow.

https://www.amrita.edu/campus/amritapuri/reach-us

Onsite contest Date is written 28-29 december. So on which date should i reach amritapuri and at which date should i return back so that it I will not miss anything ??

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