Can I use IF(ISNUMBER to find if a cell is 5 digits or more to show USA or Canada?

Could someone help me? I am learning Excel and I am trying to find a formula if a cell has 5 digits show USA, if not show Canada. But some cells have to 12345-6789 zip code, the result will show Canada.

Then I have Canada zip code R2H 0G2.

Any help is appreciated.

Thank you