tresure island python

1print("Welcome to Treasure Island.")
2print("Your mission is to find the treasure.")
3choice1 = input('You\'re at a cross road. Where do you want to go? Type "left" or "right" \n').lower()
4if choice1 == "left":
5  choice2 = input('You\'ve come to a lake. There is an island in the middle of the lake. Type "wait" to wait for a boat. Type "swim" to swim across. \n').lower()
6  if choice2 == "wait":
7    choice3 = input("You arrive at the island unharmed. There is a house with 3 doors. One red, one yellow and one blue. Which colour do you choose? \n").lower()
8    if choice3 == "red":
9      print("It's a room full of fire. Game Over.")
10    elif choice3 == "yellow":
11      print("You found the treasure! You Win!")
12    elif choice3 == "blue":
13      print("You enter a room of beasts. Game Over.")
14    else:
15      print("You chose a door that doesn't exist. Game Over.")
16  else:
17    print("You get attacked by an angry trout. Game Over.")
18else:
19  print("You fell into a hole. Game Over.")