Weekly Extreme Sudoku Competition for Dec 2 to Dec 8

Number 637, Extreme
by Crosswords Ltd. February puzzle packs Now Out!. Thanks for supporting our site.
Future Puzzle - will be submitted on the relevant day
1 2 3 4 5 6 7 8 9
A
B
C
D
E
F
G
H
J
3 9 8   1   4   7
    4     7 6    
                 
      1         6
4     6 9 5     2
7         8      
                 
    3       8    
9   2   8   5 3 1