Why did Ukraine have nuclear weapons in 1994?

In 1994, Ukraine inherited a significant stockpile of nuclear weapons from the Soviet Union after its dissolution. At that time, Ukraine was the third-largest nuclear power in the world. However, in the same year, Ukraine signed the Budapest Memorandum, agreeing to relinquish its nuclear arsenal in exchange for security assurances from Russia, the United States, and the United Kingdom, which promised to respect Ukraine's sovereignty and territorial integrity. This decision was influenced by various factors, including economic challenges and the desire for international integration.