Create an illustration of a cheerful classroom scene featuring a friendly teacher and three students. The teacher, a woman with shoulder-length brown hair, wears a light-colored dress and glasses. She holds a pointer in one hand and a book in the other. The students include a boy with short dark hair wearing a pink shirt and blue shorts, a girl with brown hair in a striped shirt and denim skirt, and another girl with black hair in a red shirt and backpack. The classroom should have a large chalkboard displaying simple math equations, a desk with colorful stationery, and a window showing a sunny day outside. Remove any specific brand elements or identifiers.