Question:
Who was the chair of Czech Social Democratic Party in Aug, 2004?

Context:
 Michal Šmarda is the chair of Czech Social Democratic Party from Jan, 2021 to Dec, 2022. 
 Bohuslav Sobotka is the chair of Czech Social Democratic Party from Jan, 2010 to Jan, 2017. 
 Jiří Paroubek is the chair of Czech Social Democratic Party from Jan, 2006 to Jan, 2010. 
 Jan Hamáček is the chair of Czech Social Democratic Party from Jan, 2018 to Jan, 2021. 
 Miloš Zeman is the chair of Czech Social Democratic Party from Jan, 1993 to Jan, 2001. 
 Vladimír Špidla is the chair of Czech Social Democratic Party from Jan, 2001 to Jan, 2004. 
 Stanislav Gross is the chair of Czech Social Democratic Party from Jan, 2004 to Jan, 2005.

Answer:
Stanislav Gross