To find the second largest element, we need to find largest element first.
Number of comparisons to find largest number = n - 1 = 64 - 1 = 63
Now, the second largest must be in the losers of first largest i.e. it might have descended down logn levels at most.
So, number of comparisons to find second largest among logn elements = logn - 1 = log(64) - 1 = 6 - 1 = 5
So total comparisons in all = (n -1) + (logn - 1) = 63 + 5 = 68