Preheat oven to 375 degrees F. Using some of the salsa, spread a light coating on the bottom of a 13x9-inch baking pan, then line it with 4 of the cut-up tortillas. Mix the chicken, remaining salsa, and corn in the pan, and top with the remaining tortilla strips. Sprinkle the cheese and olives on top of the casserole. Cover with aluminum foil and bake for 30 minutes; uncover and bake 15 minutes more. Let sit 10 minutes before serving.