How to make dash interval start from 0 anytime there is some trigger from the input

I am working on a simple dash application. I need the dcc intervals to keep refreshing my application for a task. however, whenever the user changes an input I will like the n from the intervals to start from 1 again instead of the last n.

Here is a snippet of my code

import dash
from dash_core_components.Interval import Interval
import dash_html_components as html
import dash_core_components as dcc
from dash.dependencies import Output, Input, State


# This stylesheet makes the buttons and table pretty.

external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

app = dash.Dash(__name__, external_stylesheets=external_stylesheets)

app.layout = html.Div([

    dcc.Interval(id='interval-test', interval=2000),
    dcc.Dropdown(
        id='demo-dropdown',
        options=[
            {'label': 'New York City', 'value': 'NYC'},
            {'label': 'Montreal', 'value': 'MTL'},
            {'label': 'San Francisco', 'value': 'SF'}
        ],
        value='NYC'
    ),

    html.H1(id='test-output')

])


@app.callback(Output('test-output', 'children'),
              State('interval-test', 'n_intervals'), Input('demo-dropdown', 'value'),)
def interval_update(n, val):
    ctx = dash.callback_context
    if not ctx.triggered:
        print(n)
    else:
        
    
    return n


if __name__ == '__main__':
    app.run_server(debug=True)