Sheep Speed

There is a train with a sheep on it. The sheep is running at a speed of 2 miles per hour in the same direction to the train. The train is travelling at 60 miles per hour. How fast is the sheep travelling relative to the ground? Answer to the nearest whole number.

Note: the equation to solve this question is $S=\frac {v_1 + v_2}{1 + \frac {v_1 * v_2}{c^2}}$ where $v_1$ and $v_2$ are speeds of the train and sheep, $c$ is the speed of light (300 000 000 m/s) and $S$ is the answer.