# Arithmetic operations using Raspberry Pi Pico (RP2040)
# Input is given through the Thonny Shell

# Function definitions
def add(a, b):
    return a + b

def sub(a, b):
    return a - b

def mul(a, b):
    return a * b

def div(a, b):
    if b != 0:
        return a / b
    else:
        return "Error: Division by zero"

# Main program
while True:
    print("\n=== Arithmetic Operations ===")
    print("1. Addition (+)")
    print("2. Subtraction (-)")
    print("3. Multiplication (*)")
    print("4. Division (/)")
    print("5. Exit")

    choice = input("Enter your choice (1–5): ")

    if choice == '5':
        print("Exiting program.")
        break

    num1 = float(input("Enter first number: "))
    num2 = float(input("Enter second number: "))

    if choice == '1':
        print("Result =", add(num1, num2))
    elif choice == '2':
        print("Result =", sub(num1, num2))
    elif choice == '3':
        print("Result =", mul(num1, num2))
    elif choice == '4':
        print("Result =", div(num1, num2))
    else:
        print("Invalid choice! Try again.")