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    [ http://www.resoo.org/sudoku ]

    +===+===+===++===+===+===++===+===+===+
    | 2 |   |   ||   |   | 7 || 6 |   |   |
    +---+---+---++---+---+---++---+---+---+
    |   | 9 | 4 || 6 |   |   ||   |   | 1 |
    +---+---+---++---+---+---++---+---+---+
    | 6 |   |   ||   | 2 |   ||   |   |   |
    +===+===+===++===+===+===++===+===+===+
    |   |   |   || 3 |   |   || 4 |   | 5 |
    +---+---+---++---+---+---++---+---+---+
    |   | 5 | 9 ||   |   |   ||   |   |   |
    +---+---+---++---+---+---++---+---+---+
    | 1 |   |   ||   |   | 5 ||   |   | 9 |
    +===+===+===++===+===+===++===+===+===+
    | 3 |   |   ||   | 4 |   ||   | 9 |   |
    +---+---+---++---+---+---++---+---+---+
    |   |   |   ||   | 9 | 6 || 3 |   | 8 |
    +---+---+---++---+---+---++---+---+---+
    |   |   |   || 7 | 3 |   ||   |   | 6 |
    +===+===+===++===+===+===++===+===+===+
    

    Solution :

    +===+===+===++===+===+===++===+===+===+
    | 2 | 1 | 5 || 9 | 8 | 7 || 6 | 3 | 4 |
    +---+---+---++---+---+---++---+---+---+
    | 7 | 9 | 4 || 6 | 5 | 3 || 8 | 2 | 1 |
    +---+---+---++---+---+---++---+---+---+
    | 6 | 8 | 3 || 1 | 2 | 4 || 9 | 5 | 7 |
    +===+===+===++===+===+===++===+===+===+
    | 8 | 2 | 7 || 3 | 1 | 9 || 4 | 6 | 5 |
    +---+---+---++---+---+---++---+---+---+
    | 4 | 5 | 9 || 8 | 6 | 2 || 1 | 7 | 3 |
    +---+---+---++---+---+---++---+---+---+
    | 1 | 3 | 6 || 4 | 7 | 5 || 2 | 8 | 9 |
    +===+===+===++===+===+===++===+===+===+
    | 3 | 6 | 8 || 5 | 4 | 1 || 7 | 9 | 2 |
    +---+---+---++---+---+---++---+---+---+
    | 5 | 7 | 1 || 2 | 9 | 6 || 3 | 4 | 8 |
    +---+---+---++---+---+---++---+---+---+
    | 9 | 4 | 2 || 7 | 3 | 8 || 5 | 1 | 6 |
    +===+===+===++===+===+===++===+===+===+
    

    Niveau : 3  (masque 54)
    Etude  : 229 sudoku(s)
    Debut  : Sat Oct 19 05:40:56 2019
    Fin    : Sat Oct 19 05:40:56 2019
    (c)2006 resoo.org