After the Treaty of Versailles, treaties with Austria, Hungary, Bulgaria, and the Ottoman Empire were signed. However, the negotiation of the treaty with the Ottoman Empire was followed by strife, and a final peace treaty between the Allied Powers and the country that would shortly become the Republic of Turkey was not signed until 24 July 1923, at Lausanne. Some war memorials date the end of the war as being when the Versailles Treaty was signed in 1919, which was when many of the troops serving abroad finally returned home; by contrast, most commemorations of the war's end concentrate on the armistice of 11 November 1918. Legally, the formal peace treaties were not complete until the last, the Treaty of Lausanne, was signed. Under its terms, the Allied forces left Constantinople on 23 August 1923.
Question: How many nations mentioned signed treaties after the Treaty of Versailles?
Answer: 4