Singapore is one of the cleanest nations of the world. It is strongly forbidden to throw papers or cigarette ends in the street otherwise it's a strong fine (between 200 and 400 US dollars). In the same way the chewings-gum are not proposed to the sale in Singapore. To cross out of the crosswalks, to smoke in the public places are also offences sanctioned by heavy fines. Many police officers, sometimes equipped into civil are ready to charge all offender.