At the same time as Darányi, Czechoslovak Foreign Minister František Chvalkovský also visited Germany to negotiate with German representatives. Hitler blamed Czechoslovakia for the failure of negotiations with Hungary and requested their renewal. He gave Chvalkovský a map with the Ribbentrop line and promised to guarantee new borders, based on that proposal. Back in Prague, Chvalkovský recommended to accept the Ribbentrop line. However, the Slovak autonomous government was against such a solution and hoped that it would be possible to achieve further corrections. On October 19, Tiso and Ďurčanský met with Ribbentrop in Munich and managed to persuade him to assign Košice to Czechoslovakia and to accept the prior proposal of keeping balanced minorities both in Czechoslovakia and Hungary. Czechoslovak experts prepared material that argued that the Hungarian statistics were unreliable and that Hungarian demands were not compliant with the ethnic principle but were driven by foreign policy and strategic factors. They argued that the Hungarian claim for Košice was not motivated by ethnic or historical reasons but focused on elimination of the largest communication, economic and cultural centre it the east and on the interruption of the railway to Carpatian Ruthenia and allied Romania, thus totally isolating the eastern part of the republic, which could be later annexed by Hungary. Both Tiso and Ďurčanský believed that they had persuaded Hitler. Tiso sent a letter to Prague to notify about positive results.