MinMax Sudoku Puzzle (Daily Sudoku League #196)

MinMax Sudoku puzzle is also known as Highest Difference Sudoku. I had earlier posted this Sudoku type with the title Highest Difference Sudoku (Daily Sudoku League #33) in Daily Sudoku League. There are a few variations to this Sudoku. MinMax Sudoku uses the sum of the lowest and highest number in the first three digits visible from that end. There is MinMax Difference Sudoku which uses the difference between the highest and lowest number. Similarly, we have MinMax Product Sudoku in which the product of the lowest and highest number among the first three numbers is given. I will be posting one MinMax Product Sudoku puzzle soon.
Today's MinMax Sudoku puzzle is a tough puzzle and an experienced Sudoku player should take more than 10 minutes to solve this Sudoku puzzle.

This Extra Region Sudoku Puzzle, I am posting in The League of Extraordinary Ladies & Gentlemen as the 196th Sudoku puzzle in this series.

Rules of MinMax Sudoku Sudoku Puzzle

Standard Classic Sudoku Rules apply. In addition, a number at the edge of the Sudoku grid indicates the sum of the highest and the lowest number in the first three cells in the corresponding row or column.