 
 <translate> Passage: Elections to the United States Senate will be held November 6, 2018, with 33 of the 100 seats in the Senate being contested in regular elections. The winners will serve six-year terms from January 3, 2019, to January 3, 2025. Currently, Democrats have 23 seats up for election along with 2 independents who caucus with them. Republicans have 8 seats up for election. Two of the Republican seats are open as a result of Tennessee Senator Bob Corker's and Arizona Senator Jeff Flake's pending retirements. The seats up for election in 2018 were last up for election in 2012, although some seats may have special elections if incumbents die or resign, as has already happened in Alabama and Minnesota. After the 2016 elections, some state election officials are trying to upgrade voting systems in time for this election.

Question: Based on this passage, how many senate seats are up for election in 2018?
33 <ibo> Oge: A ga-eme ntuliaka maka ndị omeiwu nke United States na Nọvemba 6, 2018, ebe a ga-eme 33 n'ime oche 100 na Senate na ntuliaka oge niile. Ndị meriri ga-eje ozi afọ isii site na Jenụwarị 3, 2019, ruo Jenụwarị 3, 2025. Ka ọ dị ugbua, ndị Democrats nwere oche iri abụọ na atọ maka ntuliaka tinyere ndị nnwere onwe abụọ na-eso ha. Ndị Republican nwere oche asatọ maka ntuliaka. Abụọ n'ime oche ndị Republican gheere oghe n'ihi na Senator Bob Corker nke Tennessee na Senator Jeff Flake nke Arizona na-echere ịla ezumike nká. Oche ndị a ga-ahọpụta n'afọ 2018 bụ nke ikpeazụ a ga-ahọpụta n'afọ 2012, ọ bụ ezie na ụfọdụ oche nwere ike inwe ntuliaka pụrụ iche ma ọ bụrụ na ndị nọ n'ọchịchị anwụọ ma ọ bụ gbaa arụkwaghịm, dịka o meworị na Alabama na Minnesota. Mgbe ntuliaka 2016 gachara, ụfọdụ ndị ọrụ ntuliaka steeti na-agba mbọ imeziwanye usoro ịtụ vootu n'oge ntuliaka a.  Ajụjụ: Dabere n'ihe a e kwuru, oche ole ka a ga-ahọpụta n'ụlọomeiwu n'afọ 2018? 33 ihe 