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

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

    Solution :

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

    Niveau : 3  (masque 51)
    Etude  : 420 sudoku(s)
    Debut  : Thu Jun 27 09:38:00 2019
    Fin    : Thu Jun 27 09:38:01 2019
    (c)2006 resoo.org