import streamlit as st

def calculate_note_average(notes):
    if not notes:
        return None
    try:
        numbers = [float(note.strip()) for note in notes.split(",")]
        return sum(numbers) / len(numbers)
    except ValueError:
        return None

st.title("Note Calculator App")
st.write("This app calculates the average of notes you input.")

notes_input = st.text_input("Enter your notes (comma-separated):", placeholder="e.g., 85, 90, 78")

if st.button("Calculate Average"):
    average = calculate_note_average(notes_input)
    if average is None:
        st.error("Please enter valid numeric values separated by commas.")
    else:
        st.success(f"The average of your notes is: **{average:.2f}**")