The weather is getting cold. Migratory birds have started to migrate to warmer places. Like the all teams, bird flocks also have a leader. Guide the leader of the yellow birds to take the birds to a warm place. You should make the leader bird fly close to the other yellow birds so that they can follow their leaders. Try to keep the whole flock together by avoiding the other kind of birds. Let's see how many birds will be in the flock in the end.