import streamlit as st

def main():
    st.title("Simple Calculator")

    num1 = st.number_input("Enter first number", format="%f")
    num2 = st.number_input("Enter second number", format="%f")
    
    operation = st.selectbox("Select operation", ("Add", "Subtract", "Multiply", "Divide"))

    if st.button("Calculate"):
        if operation == "Add":
            result = num1 + num2
            st.success(f"Result: {result}")
        elif operation == "Subtract":
            result = num1 - num2
            st.success(f"Result: {result}")
        elif operation == "Multiply":
            result = num1 * num2
            st.success(f"Result: {result}")
        elif operation == "Divide":
            if num2 != 0:
                result = num1 / num2
                st.success(f"Result: {result}")
            else:
                st.error("Cannot divide by zero!")

if __name__ == "__main__":
    main()