Hsueh Shih-ling, also known as 40 or MC40, is a Taiwanese actor, singer, rapper, songwriter, and television presenter. Hsueh was known as MC40 from award-winning hip-hop band Da Mouth, with DJ Chung Hua, Harry Chang, and Aisa, before embarking on a career in acting. He writes most of Da Mouth's song lyrics and is considered one of the best and fastest rappers in Taiwan with his multi-language rapping ability.