Who performed in both Welcome to the Show and the band f(x)?
Welcome to the Show (TV series):  It starred Im Seulong, Sulli Choi, Nichkhun, Kim Jang-hoon, and Kim Kwang-kyu. Sulli: Choi Jin-ri (born March 29, 1994), better known by her stage name Sulli, is a South Korean actress and model. Sulli:  She is a former member of South Korean girl group f(x).
i don't know