({2} magic symbol) ({R} magic symbol) plus an additional amount of ({R} magic symbol) available equal to three minus the number of +1/+1 counters on Runaway Steam-Kin available.
Steps
If Runaway Steam-Kin has three or more +1/+1 counters on it, activate it by removing three +1/+1 counters from it, adding ({R} magic symbol) ({R} magic symbol) ({R} magic symbol) .
Runaway Steam-Kin triggers, putting a +1/+1 counter on it.
Activate Grinning Ignus by paying ({R} magic symbol) and returning it from the battlefield to your hand, adding ({C} magic symbol) ({C} magic symbol) ({R} magic symbol) .