The Treaty of Sèvres was signed by the Ottoman Empire and was followed by the occupation of Artvin by Georgian forces on 25 July. The Treaty of Alexandropol  was the first treaty signed by the Turkish revolutionaries. It nullified the Armenian activities on the eastern border, which was reflected in the Treaty of Sèvres as a succession of regions named Wilsonian Armenia. The 10th item in the Treaty of Alexandropol stated that Armenia renounced the Treaty of Sèvres, which stipulated Wilsonian Armenia. After the peace agreement with the Turkish nationalists, in late November, a Soviet-backed Communist uprising took place in Armenia. On 28 November 1920, the 11th Red Army under the command of Anatoliy Gekker crossed over into Armenia from Soviet Azerbaijan. The second Soviet-Armenian war lasted only a week. After their defeat by the Turkish revolutionaries the Armenians were no longer a threat to the Nationalist cause. It is also possible to claim that had the ADR been content with the boundaries as of 1919, it could have shown more resistance to the Bolshevik conquest, both internally and externally, but that was not how things happened. On 16 March 1921, the Bolsheviks and Turkey signed a more comprehensive agreement, the Treaty of Kars, which involved representatives of Soviet Armenia, Soviet Azerbaijan, and Soviet Georgia. The arms left by the defeated ADR forces were sent to the west for use against the Greeks.
Question: How many months after the 11th Red Army crossed over into Armenia did the Bolsheviks and Turkey sign the Treaty of Kars?
Answer: 4