Logic Masters Deutschland e.V.

Standard sudoku rules applies. Fill the grid with numbers from 1 to 9 so each digit occurs exactly once in every row, column and 3x3 box.

Four digits surrounded the circle mean there are 2 odd numbers and 2 even numbers.The number in the circle show the sum of the biggest and smallest number around the circle.

All possible circle are given. In other words, places without a circle don't have the same amount of odd numbers and even numbers.

F-puzzles link

This puzzle is made by Old Miles from China in 2017.It's a variation from type good.