[Tutor] elif statement doesn't work

[hongerlapjes]

For school I have to make a simple roulette game.
If the user inputs "STOP", the game starts. But I cant seem to make the 
input STOP.  ValueError: invalid literal for int() with base 10: 'STOP'
What am I doing wrong?

"""
ROULETTESPEL
"""
import random
invoer = ["STOP"]
for x in range(37):
    invoer.append(x)


getallen = []

def roulette ():
     print("Rien ne va plus.")
     winnendgetal=(random.randint(0,36))
     print("De uitkomst is", winnendgetal)

     for winnendgetal in getallen:
         fiches +=35
         print("Je hebt gewonnen en je hebt nu" , fiches, "fiches.")
     else:
         if fiches == 0:
             print("GAME OVER")

def start ():
     fiches = 10
     print("Je hebt", fiches, "fiches!")

     while fiches > 0:
         inzet=input("Op welk getal wil je inzetten?"'\n')
         print(inzet)

         if int(inzet) >= 0 and int(inzet) <= 36 :
             fiches -= 1
             getallen.append(inzet)
             print(getallen)
             print("Je hebt nog", fiches, "fiches over.")

         elif str(inzet) == "STOP" :
                 roulette()

         else:
                 start()
start ()
roulette ()