def arbre="""{"name":"flare","children":[{"name":"Algèbre","children":[{"name":"Nombres Fractionnels","children":[{"name":"Addition fractionnelle","size":8.333333333333334},{"name":"Division fractionnelle","size":10.0},]},{"name":"nombre entier","children":[{"name":"division entière","size":15.0},]},]},{"name":"Geometrie dans l'espace","children":[{"name":"projection dans l'espace","children":[{"name":"sous chapitre1 projection dans l'espace","size":10.0},{"name":"sous chapitre2 projection dans l'espace","size":15.0},]},]},{"name":"Physique","children":[{"name":"Onde","children":[{"name":"Onde circulaire","size":15.0},]},]},]}"""