Wall of China

The puzzle "Wall of China" (aka Slitherlink, Fences, Takegaki, Loop the Loop, Loopy, Ouroboros, Suriza, Dotty, Dilemma) is a rectangular table with numbers in which you need to draw a closed path that runs along the borders of the cells. The numbers (from 0 to 3) are equal to the number of contour segments along the cell perimeter. If the number is not specified, the number of segments can be any.