A delve into extraordinary chess problems: Selfmate 2

(Continuing the series from here)

Here is a second selfmate puzzle (also relatively easy, but beware the traps!). It is by C. R. Flood from 1967, and is puzzle 81 in The Book of Extraordinary Chess Puzzles:

White to play and selfmate in three.
As a reminder: "In a 'selfmate' problem White plays to force Black to checkmate him - a sort of chess suicide."

Here is an analysis board for you to play around with.

Answer

This seems to work

1. Ra4, c6 2. Rca5, c5 3. c4, g4