A thin wire carrying a steady current \(I\) lies entirely in the \(xy\)-plane. The wire consists of three connected sections: a semi-infinite straight wire along the line \(y = R\) carrying current in the \(+x\)-direction from \(x = -\infty\) to \(x = 0\), a semicircular arc of radius \(R\) centered at the origin that carries current clockwise from \((0, R)\) to \((0, -R)\), and a semi-infinite straight wire along the line \(y = -R\) carrying current in the \(-x\)-direction from \(x = 0\) to \(x = -\infty\).

What is the magnitude of the net magnetic field at the origin in terms of \(I\), \(R\), and fundamental constants?