How to put many RenderTextures into Compute Shader

When I want to put many Texture2Ds into a Compute Shader and do something(like mixing or..) on them.

I can create a Texture2DArray to put the Texture2Ds together,

And in Compute Shader, it is also declared as Texture2DArray.

But now i have many RenderTexture(maybe 50)

i can only do the thing like this in Compute Shader:

Texture2D RT0
Texture2D RT1
Texture2D RT2
..
Texture2D RT49

it really works and can finish my program,
but it is lack of efficiency.

i want to put only one Array that consist of many RenderTexture into a Compute Shader,

What is the correct way to do this ??