import streamlit as st

def add(a, b):
    return a + b

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

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

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

st.title("Functional Calculator")

col1, col2 = st.columns(2)

# Display input fields
first_number = col1.number_input("Enter first number", key="first_number")
second_number = col2.number_input("Enter second number", key="second_number")

# Create buttons with clear and concise labels
add_button = st.button("Add", key="add_button")
subtract_button = st.button("Subtract", key="subtract_button")
multiply_button = st.button("Multiply", key="multiply_button")
divide_button = st.button("Divide", key="divide_button")

# Perform calculations based on button clicks
if add_button:
    result = add(first_number, second_number)
    st.write("Result:", result)
elif subtract_button:
    result = subtract(first_number, second_number)
    st.write("Result:", result)
elif multiply_button:
    result = multiply(first_number, second_number)
    st.write("Result:", result)
elif divide_button:
    result = divide(first_number, second_number)
    st.write("Result:", result)