One Way flight to Brazil

[Ste IRL]

Hi...
This is my first POST..hope this goes well...

Im flying to RIO and Im gonna buy a bike there and begin my first trans continental bike ride to Alaska.

If I arrive into Brazil without an Onward flight will they allow me in the country? ?

I thought I might get a cheap flight to another south american counrty(that im not even gonna use), but it seems to cost at a minimum €300 !!!

So I was wondering will they allow me in without an onward flight or is there any other way to be allowed into the country without wasting the €300?

Any info Much Appreciated, Thanks