number-plus-reverse-number-equals-n

number + reverse number = n

Find a number that number + reverse number = given number

Notes: always return the lowest possible number

Examples

if you got 44 you return 13, beacause 13 + 31 = 44
646 = 125, 125 + 521 = 646
110 = 19, 19 + 91 = 110