integer swapWins = 0, stayWins = 0, winner, choice, reveal, other
atom t0 = time()

for game=1 to 1_000_000 do
    winner = rand(3)
    choice = rand(3)
    while 1 do
        reveal = rand(3)
        if reveal!=winner and reveal!=choice then exit end if
    end while
    stayWins += (choice==winner)
    other = 6-choice-reveal     -- (as 1+2+3=6, and reveal!=choice)
    swapWins += (other==winner)
end for
printf(1, "Stay: %,d\nSwap: %,d\nTime: %3.2fs\n",{stayWins,swapWins,time()-t0})