Which alliance did russia leave when it dropped out of the war?

the Treaty of Brest-Litovsk was a peace treaty signed on 3 March 1918 between the new Bolshevik government of Soviet Russia and the Central Powers (Germany, Austria-Hungary, Bulgaria, and the Ottoman Empire), that ended Russia's participation in World War I. The treaty was signed at Brest-Litovsk (Polish: Brześć Litewski; since 1945 Brest), after two months of negotiations. The treaty was agreed upon by the Bolshevik government to stop further advances by German and Austro-Hungarian forces. According to the treaty, Soviet Russia defaulted on all of Imperial Russia's commitments to the Triple Entente alliance

i believe he should not do investment b

they were all fought in the middle east during ww1