Differential Equations Part 2

The area enclosed by the closed curve C given by the differential equation ‌

dy

dx

+‌

x+a

y−2

=0,y(1)=0 is 4π.
Let P and Q be the points of intersection of the curve C and the y-axis. If normals at P and Q on the curve C intersect x-axis at points R and S respectively, then the length of the line segment RS is