Strange operations doubt (UTMOPR)

In the above question i have doubt .In this question after sum of all the values in the array .we have to add a value that is strictly greater than the sum .Here how i have to increment the sum such that its value is greater than the previous sum.

Taking the example given with the question, if array = 5, 7, then sum = 12
now we will add 13 to the array, new sum = 25,
then we can add 26, new sum = 51
and finally we will add 52, which is even!