Air is contained in a frictionless piston-cylinder arrangement as shown in the figure.

The atmosphere pressure is $100$ kPa and the initial pressure of air in the cylinder is $105$ kPa. The area of piston is $300 \: cm^2$. Heat is now added and the piston moves slowly from its initial position until it reaches the stops. The spring constant of the linear spring is $12.5$ N/mm. Considering the air inside the cylinder as the system, the work interaction is _________ J (round off to the nearest integer)