Answer based on context:

On 2 May, the German capital city, Berlin, fell to the Red Army. On 8 May 1945, the Germans surrendered unconditionally and the war in Europe officially ended. The Italians had quit the war in 1943, the Bulgarians in 1944, and the Hungarians earlier in 1945. Despite the German capitulation, however, sporadic fighting still took place in Yugoslavia. On 7 May, Zagreb was evacuated, on 9 May, Maribor and Ljubljana were captured by the Partisans, and General Alexander Löhr, Commander-in-Chief of Army Group E was forced to sign the total surrender of the forces under his command at Topolšica, near Velenje, Slovenia, on Wednesday 9 May 1945. Only the Croatian and other anti-Partisan forces remained. From 10 to 15 May, the Yugoslav Partisans continued to face resistance from Croatian, and other anti-Partisan forces throughout the rest of Croatia and Slovenia. The Battle of Poljana, the last battle of World War II in Europe, started on 14 May, ending on 15 May 1945 at Poljana, near Prevalje in Slovenia. It was the culmination and last of a series of battles between Yugoslav Partisans and a large  mixed column of German Army  soldiers together with Croatian Ustaše, Croatian Home Guard, Slovenian Home Guard, and other anti-Partisan forces who were attempting to retreat to Austria.

How many days after Berlin fell to the Red Army did Germany surrender?
6