Oh, I wouldn't worry too much about 'complex carbohydrates' they are something different to the amino acids from which protein is composed, though they coexist (along with small amounts of fat, and other nutrients) in carb dense / starchy foods such as grains and beans.

Carbs come in both 'simple' and 'complex' forms, 'simple' carbs (or sugars such as sugar/sucrose, honey, high fructose corn syrup, maple syrup etc.) are comprised of only one or two molecules and are swiftly broken down by the body to create energy.

Complex carbohydrates (or starches such as bread, potatoes, rice etc.), are comprised of strings of many molecules, it takes the body longer to break these down into energy (a good thing) than it does simple carbs / sugars.

Typically, especially if you're hoping to avoid diabetes for example, you should try to minimise or exclude 'simple carbs' where you do eat 'complex carbs' consume them in their unrefined (or less refined) state. The fibre in wholefoods slows the breaking down of complex carbs into simple carbs even further (again, a good thing.)