Body of Research by paying ({G} magic symbol) ({G} magic symbol) ({G} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) , creating a 0/0 Fractal creature token and putting a number of +1/+1 counters on it equal to your deck size.
Cast
Sin either from your hand or from the command zone by paying ({5} magic symbol) ({G} magic symbol) ({U} magic symbol) plus commander tax if applicable. As it enters, remove all the counters from the Fractal and put twice that many +1/+1 counters on
Sin.
Kill
Sin. When it dies, it second ability triggers, putting its counters on
Sage of Hours and shuffling
Sin into your library.
Activate
Sage of Hours by removing all +1/+1 counters from it, causing you to get an extra turn for each five +1/+1 counters removed from it.
Notes
You can remove counters from other permanents in step 2 to get more counters as desired. The number of extra turns you will get will maximize using the following formula: 2*(your deck size + the number of counters on artifacts, creatures and enchantments)/5, rounded down. If desired, you can take two turns to execute the combo to spread the mana cost out by doing step 1 the first turn and all other steps on the second turn.