My flights via Russia,if I stay on airport only,will I need a visa?

Question

I have a schengen visa and I'm an Indian.I need to travel to Nice but the most appropriate flight for me is via Russia.If I stay on the airport only,will I need a visa?Also,will I need a visa if a flight is via Switzerland?What is the limits of hours I can stay on the airport of Switzerland and Russia if my flights via them?Please answer asap.thanks.