Convert Hex to Base64 without using built-in language fucntions

Max Reward: 100

The string:

496620796f752061726520612070726f6772616d6d696e6720477572752c207468697320776f756c642062652061207069656365206f662063616b652e2e2e

Should produce:

SWYgeW91IGFyZSBhIHByb2dyYW1taW5nIEd1cnUsIHRoaXMgd291bGQgYmUgYSBwaWVjZSBvZiBjYWtlLi4u

Please don't use any built-in functions.

Input Format

hexadecimal string

Output Format

base64 encoded string

Sample Input

496620796f752061726520612070726f6772616d6d696e6720477572752c207468697320776f756c642062652061207069656365206f662063616b652e2e2e

Sample Output

SWYgeW91IGFyZSBhIHByb2dyYW1taW5nIEd1cnUsIHRoaXMgd291bGQgYmUgYSBwaWVjZSBvZiBjYWtlLi4u

Memory Limit

512M