Between terminals X and Y, a circuit is built as follows: A branch contains a 6Ω resistor (R1) in series with a 3Ω resistor (R2). In parallel with this branch, a single 4Ω resistor (R3) connects directly from X to Y. An ideal wire with negligible resistance joins the junction between R1 and R2 directly back to terminal X. Calculate the equivalent resistance between terminals X and Y.