PUZZLE NO. 401: QUADRUPLES - REGION SUM LINES HYBRID SUDOKU

 

RULES: Classic Sudoku rules apply. Digits in circles must appear in the surrounding four cells, in some order. For each line, digits on the line have an equal sum N within each box it passes through. If a line passes through the same box more than once, each individual segment of such a line within that box sums to N separately. 

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