je te montre comment faire avec d'autre chiffre
pgcd(72, 132) = pgcd (72, 132 - 72) = pgcd (72, 60)
pgcd (72, 60) =pgcd (72 - 60, 60) = pgcd (12, 60)
pgcd (12, 60) = pgcd (12, 60 -12) = pgcd (12, 48)
pgcd (12, 48) = pgcd (12, 48 - 12) = pgcd (12,36)
pgcd (12, 36) = pgcd (12, 36 - 12) = pgcd (12, 24)
pgcd(12, 24) = pgcd (12, 24 - 12) = pgcd (12, 12)
