Try this: Garmoshka Tutorial - it shows you how the system works and is a good start if you want to learn how to play one. Basically your scale follows a zig-zag pattern along the keyboard, except there are often some out-of-sequence accidentals at the chin end.

And "Garmon" or its diminutive "Garmoshka" is the general Russian word for a folk accordion (as opposed to "Bayan" for the big B system chromatic or piano accordion). In this case "Vostok" is almost certainly a brand name.