def ind_maximum(L):
    maximum=0
    rang=0
    for i in range(len(L)):
        if L[i]>maximum:
            maximum=L[i]
            rang=i
    return rang

def second_max(L):
    i=0
    while i<len(L):
        for j in range(i+1,len(L)):
            if L[j]> L[i]:
                for elem_3 in L[j+1:]:
                    if elem_3>elem:
                        i=i+1
                return i
            i=i+1
    return None

def nb_mots(s):
    liste=s.split()
    return len(liste)

def mot_plus_long(s):
    liste=s.split()
    l=liste[0]
    for elem in liste[1:]:
        if len(elem)>l:
            l=elem
    return l

def frequences_lettres(s):
    d={}
    for elem in s:
        if elem in d:
            d[elem]+=1
        else:
            d[elem]=1
    return d

def moyenne(L):
    somme=0
    for elem in L:
        somme+=elem
    return somme/len(L)

def meilleur_etudiant(notes):
    maximum=0
    meilleur=""
    for elem in notes:
        if moyenne(notes[elem])>maximum:
            maximum=moyenne(notes[elem])
            meilleur=elem
    return meilleur

def compter(L, x):
    if len(L)==0:
        return 0
    if L[0]==x:
        return 1+compter(L[1:],x)

def croissante(L):
    if len(L)=<1:
        return True
    return L[0]>croissante(L[1:])


def puissance(a, n):
    if n==0:
        return 1