ans would be 5.
explaination - 1st notice - the two for loops are separate that is 2nd loop in not inner loop of 1st loop.
now in the 1st loop--
j = 0 | i = 2^40
j = 1 | i = 2^39
j = 2 | i = 2^38
.... and so on until
j = 39 | i = 2^1
j = 40 | i = 2^0
at the end of 1st for loop j = 40, so mathematically the for loop is finding floor of (log2(n))
now in 2nd for loop, similarly it is finding floor of (log2(j)) that is floor( log2(40)) = 5