One-year interest rates in Bulgaria are currently 3.30%, whe…

One-year interest rates in Bulgaria are currently 3.30%, whereas in the U.S. they are 4.20%.  If the current spot rate for the Bulgarian lev (which means “lion”, abbreviation: BGN) is BGN 1.8004 per USD… What must be the one-year forward rates in Bulgaria be in order for arbitrage opportunities not to exist?