Convert from javascript to c#

Hi can anyone help me convert this code from javascript to c#?

var screenPos = Input.MousePosition;

screenPos.z = 2;

var worldPos = camera.ScreenToWorldPoint(screenPos);

var newInstance = Instantiate(prefab, worldPos, Quaternion.identity);

Vector3 screenPos = Input.mousePosition;

screenPos.z = 2;

Vector3 worldPos = camera.ScreenToWorldPoint(screenPos);

GameObject newInstance = Instantiate(prefab, worldPos, Quaternion.identity) as GameObject;

Edit: fixed a mistake I made there.