[SOLVED]RGBA mask Normal Map trouble

[SOLVED]
My shader uses RGBA mask and that correctly works with diffuse(albedo). It contains Ambient Occlusion texture,RGBA mask texture(Temporary alpha is a separated texture) and 4 tileable textures(I use this shader for houses)
The problem is that I can`t create normals the same way as diffuse. I`m not able to convert half3(diffuse result) to half4 which "UnpackNormals" uses.Please help me to add Normal Maps using my mask!

Sorry,I`ve just placed "half4" everywhere instead of "half3" and it works!!