# First, we'll create a dictionary to store the users and their corresponding passwords
users = {}

# Now, we'll define a function to handle signup
def signup():
  # Prompt the user to enter a username and password
  username = input("Enter a username: ")
  password = input("Enter a password: ")
  # Add the username and password to the users dictionary
  users[username] = password
  print("Signup successful!")

# Next, we'll define a function to handle login
def login():
  # Prompt the user to enter their username and password
  username = input("Enter your username: ")
  password = input("Enter your password: ")
  # Check if the username and password match a set in the users dictionary
  if (username in users) and (users[username] == password):
    print("Login successful!")
  else:
    print("Invalid username or password. Please try again.")

# Now, we'll prompt the user to choose between signup and login
while True:
  choice = input("Would you like to signup or login? (s/l) ")
  if choice == 's':
    signup()
  elif choice == 'l':
    login()
  else:
    print("Invalid choice. Please try again.")