Divide the four lines in the grid into two pairs. The lines in a pair are copycats of each other, i.e. they have the same composition of digits. E.g. if one line has two 3s, five 4s and a 9, then the other one also has two 3s, five 4s and a 9. The order of the digits is not necessarily the same on the two lines. The two lines in the grid with a circle on one end are an average arrow and a thermometer. The two lines without a circle are a region sum line and a german whispers line. The solver has to deduce which line obeys which rule. Average Arrow: The digit in the circle is the average (exact, not rounded) of the digits on the line. Thermometer: The digits have to increase along the thermometer, starting from its bulb. Region Sum Line: The line is cut into multiple segments by the box borders, each summing to the same number. German Whisper: Two neighboring digits have a difference of 5 or more.