Circle

If one of the diameters of the circle $x^2+y^2-10 x+4 y+13=0$ is a chord of another circle $\mathrm{C}$, whose center is the point of intersection of the lines $2 x+3 y=12$ and $3 x-2 y=5$, then the radius of the circle $\mathrm{C}$ is :