# ETAPE 1
import datetime

# ETAPE 2
toutesLesDates = []

reponse = 'oui'
while (reponse.lower() == 'oui'):
    DD = int(input('Jour: '))
    while(1 <= DD <= 31):
        DD = int(input('Jour: '))

    MM = int(input('Mois: '))
    while (1 <= MM <= 12):
        MM = int(input('Mois: '))

    YYYY = int(input('Année: '))
    while (1000 <= YYYY <= 9999):
        YYYY = int(input('Année: '))

    toutesLesDates.append(datetime.datetime(YYYY, MM, DD))
    reponse = str(input('Saisir une autre date? '))

# ETAPE 3
toutesLesDates.sort()
for date in toutesLesDates:
    print(date)