How to increase only the height on my video?

Hello everyone!

I want to ask you how can I make custom change on the height of my video? An example is the following: I made a video for my client with a resolution 1000 x 1000. Now he wants to add a line of text above the video. How can I increase the sequence only by height without changing the width of the video.  (This can be easily done if I edit image in Photoshop or other image editor, but how can I make this for video in Adobe Premiere? )

I tried to change it from menu  "Sequence" and "Effect control" but it seems that the height and width are connected and the both resized when I want to rezise only height. 

I hope you understand my question. 

Thanks in advance!