What sort of excercise?

You cant get stamina in one day. You have to maintain it. Here you go. For example you run for a half km at your first day. then next day make it 1km if you find half km easy to complete. then like this go on and increase your distance day by day. Same is the thing that you have to follow for everything else like push ups chin ups, day 1st do 10 then next day 15 and so on. and rest you would have understand. you will maintain stamina within 2 weeks for sure. thanks