Please answer a question about the following article about Dissolution of the Soviet Union:

On April 6, 1990, the Lviv City Council voted to return St. George Cathedral to the Ukrainian Greek Catholic Church. The Russian Orthodox Church refused to yield. On April 29–30, 1990, the Ukrainian Helsinki Union disbanded to form the Ukrainian Republican Party. On May 15 the new parliament convened. The bloc of conservative communists held 239 seats; the Democratic Bloc, which had evolved into the National Council, had 125 deputies. On June 4, 1990, two candidates remained in the protracted race for parliament chair. The leader of the Communist Party of Ukraine (CPU), Volodymyr Ivashko, was elected with 60 percent of the vote as more than 100 opposition deputies boycotted the election. On June 5–6, 1990, Metropolitan Mstyslav of the U.S.-based Ukrainian Orthodox Church was elected patriarch of the Ukrainian Autocephalous Orthodox Church (UAOC) during that Church's first synod. The UAOC declared its full independence from the Moscow Patriarchate of the Russian Orthodox Church, which in March had granted autonomy to the Ukrainian Orthodox church headed by Metropolitan Filaret.

Who became the new patriarch of the UAOC in 1990?
Metropolitan Mstyslav