A solid closed vessel contains nitrogen at a temperature of 300 K and a pressure of P₀. A certain amount of atomized liquid nitrogen is injected into the vessel at a boiling point of 77.3 K, which quickly evaporates. After a long time, when the temperature becomes equal to the initial temperature, a pressure of 2P₀ is set in the vessel. Determine what was the minimum nitrogen pressure in the vessel after injection. The molar heat capacity of nitrogen is c = (5/2)R, and its molar heat of vaporization is 5.53 kJ/mol.