prog.cs(3,7): error CS0246: The type or namespace name `UnityEngine' could not be found. Are you missing an assembly reference?
prog.cs(5,36): error CS0246: The type or namespace name `MonoBehaviour' could not be found. Are you missing an assembly reference?
prog.cs(12,29): error CS0246: The type or namespace name `Texture2D' could not be found. Are you missing an assembly reference?
Compilation failed: 3 error(s), 0 warnings