Please answer a question about the following article about Cubism:

The influence of cubism extended to other artistic fields, outside painting and sculpture. In literature, the written works of Gertrude Stein employ repetition and repetitive phrases as building blocks in both passages and whole chapters. Most of Stein's important works utilize this technique, including the novel The Making of Americans (1906–08). Not only were they the first important patrons of Cubism, Gertrude Stein and her brother Leo were also important influences on Cubism as well. Picasso in turn was an important influence on Stein's writing.

What was Gertrude Stein's brother's name?
Leo