| | | ︖ | 1. | | | | | 2. | | | | 3. | 4. | | | ︖ | 1. | | | 2. | 2 | | 3. | | 4. | | ︵ ︶ | | ︖ | | | 15 30 ︔ | 15 30 ︔ | | | ︖ | | | | | | ︵ ︶ | |