Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English natural number Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English Simple English