Task: Sentence Expansion
Input (English): Zakarpattia Oblast was formally established on January 22 , 1946 after the annexation of Subcarpathian Rus lands to the Ukrainian Soviet Socialist Republic .
Output (English): Zakarpattia Oblast was established on 22 January 1946 , after the resignation of Czechoslovakia on the territory of " Subcarpathian Ruthenia " , annexed forcibly by the Soviet Union and attached to the Ukrainian Soviet Socialist Republic , under a treaty between Czechoslovakia and the Soviet Union .