What exercises should I do to get a flat stomach in a week?

ok i don’t need to do anything extreme. Im pretty skinny. But I have an inch or two that i wanna lose off of my stomach and i need it done within a week. I hear crunches help but i also hear they don’t. So im unsure about what to do. I know diet is a very important part to getting a flat stomach so any food suggestions? Thank u guys! <3