Maximum Open Trade Size Limiter

I need an EA/Script which can do 1 thing - limit the total position size in an account to a <input> number of my choice. I want the <input> to be a total number of lots open at any one time. 

I want to run the Trade Size Limiter EA/script in conjunction with a second EA running on 36 other currency pairs. 

The Trade Size Limiter EA should not interfere in any way with the closing of existing trades or updating SL/TP.

It should simply guarantee that the trade size at any one time does not exceed a given <input> number.

In Summary, if the other EA wants to OPEN a new trade, the order should be ignored if the existing trade size is already at the maximum <input> amount.

Please message me with any questions.