When a gas filled in a closed vessel is heated by raising the temperature by $1^\circ\mathrm{C}$, its pressure increases by $0.4\%$. The initial temperature of the gas is $\_\_\_\_$ $K$.
When a gas filled in a closed vessel is heated by raising the temperature by $1^\circ\mathrm{C}$, its pressure increases by $0.4\%$. The initial temperature of the gas is $\_\_\_\_$ $K$.