The major product obtained in the following reaction is :

Which is the most suitable reagent for the following transformation ?

The major product of the following reaction

Let N be the set of natural numbers and two functions f and g be defined as f, g : N $$ \to $$ N such that

f(n) = $$\left\{ {\matrix{ {{{n + 1} \over 2};} & {if\,\,n\,\,is\,\,odd} \cr {{n \over 2};} & {if\,\,n\,\,is\,\,even} \cr } \,\,} \right.$$;

      and g(n) = n $$-$$($$-$$ 1)ⁿ.

Then fog is -