ex_e3a

def p1(N):
    if N==1:
        return False
    if N==2:
        return True
    for d in range(2,N):
        if N%d==0:
            return False
    return True
def nextprime(N):
    k=N+1
    while p1(k)==False:
        k+=1
    return k
def jumeau(N):
    p=nextprime(N)
    while True:
        if p1(p+2):
            return [p,p+2]
        p=nextprime(p)
def lesjumeaux(N):
    l,k=[],0
    while True:
        l1=jumeau(k)
        if l1[1]>N :
            return l
        else:
            l.append(l1)
        k=nextprime(l1[0])-1