Elimination Tactics

It is known that the production of precious crystals - not an easy thing. We offer you a large field with semi-precious stones, but to get them, will have to work hard not to pick and shovel, and the loaf. Having selected, you must completely clear the field of gems. Take two identical pebbles, if they are close, if the crystals are at a distance, and between them are gems of a different color, they also would climb.