Sevens

Liisa and Markku are entirely different in temperament and constantly at sixes and sevens.

The orchestra played at sixes and sevens.

Surprisingly, the number seven is consistently considered lucky, even for very different cultures. Everyone knows that in western casinos, a person wins at the slot machines if they get triple sevens, and seven is the most probable outcome of rolling two dice. But even the ancient Greeks thought seven was a special number.