How much will i have to run to lose all of my stomach fat?

I only have little bit of stomach fat, i can see a 4-pack when i flex, but how much will i have to do to get rid of the rest of the stomach fat in 2 or 3 weeks? Im willing to do anything for as long as i need to, to acomplish my goal, so if someone can give me a lil plan, or some excersizes that will work, i will be so grateful!