Activate Marath by paying ({1} magic symbol) and removing a +1/+1 counter from it, giving itself two +1/+1 counters.
Activate Marath by paying ({1} magic symbol) and removing a +1/+1 counter from it, giving Cryptic Trilobite two +1/+1 counters.
Activate Cryptic Trilobite's first ability by removing a +1/+1 counter from it, adding ({C} magic symbol) ({C} magic symbol) that can only be spent to activate abilities.
Repeat for infinite +1/+1 counters on Cryptic Trilobite.
Activate Cryptic Trilobite's first ability by removing a +1/+1 counter from it, adding ({C} magic symbol) ({C} magic symbol) that can only be spent to activate abilities.
Activate Marath's ability by paying ({1} magic symbol) and removing a +1/+1 counter from it, giving itself two +1/+1 counters.
Repeat from step 5 to get infinite ({C} magic symbol) that can only be spent to activate abilities and to put infinite +1/+1 counters on Marath, with which you can use to activate Marath's ability infinite times.
Results
Infinite +1/+1 counters.
Infinite colorless mana that can only be used to activate abilities.