dmateriel = {
    'costume_A': {'nb': 3, 'volume':2, 'poids':1},
    'costume_B': {'nb': 1, 'volume':6, 'poids':2},
    'chaise_bois': {'nb': 40, 'volume':50, 'poids':4},
    'chapeau_A': {'nb': 2, 'volume':3, 'poids':1},
    'chapeau_B': {'nb': 4, 'volume':7, 'poids':1},
}

def tab_clefs_tab_volumes(dmatos):
    tab_clefs = []
    tab_volumes = []
    for clef, dico in dmatos.items():
        tab_clefs.append(clef)
        tab_volumes.append(dico['volume'])
    return tab_clefs, tab_volumes

def clefs_triees_selon_volume(dmatos):
    tab_clefs, tab_volumes = tab_clefs_tab_volumes(dmatos)
    for i in range(len(tab_clefs)-1):
        for j in range(i+1, len(tab_clefs)):
            if tab_volumes[i] > tab_volumes[j]:
                # On échange les volumes
                tab_volumes[i], tab_volumes[j] = tab_volumes[j], tab_volumes[i]
                # On échange les clefs correspondantes
                tab_clefs[i], tab_clefs[j] = tab_clefs[j], tab_clefs[i]
    return tab_clefs

def remplissage(dmatos, vmax):
    vol = 0
    clefs_triees = clefs_triees_selon_volume(dmatos)
    i = len(clefs_triees) - 1
    elements = []
    while i >= 0 and vol < vmax:
        clef = clefs_triees[i]
        if dmatos[clef]['nb'] == 0:
            i -= 1
        elif vol + dmatos[clef]['volume'] <= vmax:
            vol += dmatos[clef]['volume']
            elements.append(clef)
            dmatos[clef]['nb'] -= 1
        else:
            i -= 1
    return elements

def nb_voitures(dmatos, vmax):
    elements = remplissage(dmatos, vmax)
    if elements == []:
        return 0
    n = 1
    while len(elements) != 0:
        elements = remplissage(dmatos, vmax)
        n += 1
    return n

n = 0
for clef in dmateriel:
    n += dmateriel[clef]['nb']
print(n)