CN-LEAGUE 2002 Problem 1

In $\triangle ABC$ , $\angle A = 60$ , $AB>AC$ , point $O$ is the circumcenter and $H$ is the intersection point of two altitudes $BE$ and $CF$ . Points $M$ and $N$ are on the line segments $BH$ and $HF$ respectively, and satisfy $BM=CN$ . Determine the value of $\frac{MH+NH}{OH}$ .