Ameliorate the YALTA Conference

Directions:
There are five missing commas, and a missing COLON in line 3. In total, there are two complete sentences.  

The yalta Conference sometimes called the Crimea Conference
was held February 4–11 1945 was the World War II meeting of the Big Three President Franklin D. Roosevelt, Prime Minister Winston Churchill and Premier Joseph Stalin  the purpose of Yalta was to discuss Europes post-war reorganization.

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Suggested correction: 
The Yalta Conference, sometimes called the Crimea Conference, was held February 4–11, 1945, was the World War II meeting of the Big Three:   President Franklin D. Roosevelt, Prime Minister Winston Churchill, and Premier Joseph Stalin. The purpose of Yalta was to discuss Europe's post-war reorganization.