Cast Beck, fusing it if you have the mana available, otherwise using some other way to draw a card.
Instead of drawing a card, create a 2/2 bear token.
Beck triggers.
Sacrifice the bear to Ashnod's Altar for ({C} magic symbol) ({C} magic symbol) .Allow Mana Echoes to resolve, adding ({C} magic symbol) for each bear you control.
Before Beck's trigger resolves, activate Words of Wilding, replacing your next draw with the creation of a 2/2 bear.
Repeat for infinite colorless mana, then repeat without sacrificing the bears for infinite bears.