How to combine elements inside a vector image (svg) into one?

Question

Design

I have a vector map with the subjects of the Russian Federation. Each subject is a separate path in the svg image. But some parts of this image are not together ( not in one path, but in several ). How can I merge them into one so that it can stand out as one?


To solve it, I downloaded inkscape and do the following (but it doesn't work out very well):
1) I select the elements to be combined with the F1 tool, click "Contour --> Sum".
Result: The element is not visible.

2) I select with the F1 tool the elements that need to be combined, click "Path --> Outline Stroke" and "Path --> Amount".
Result: The element is visible, but it just wraps each object in a group, there is no common path.

Answer 1

Ctrl + Num+or Path - Union.