Shikaku 6887

Normal sudoku rules apply.

Divide the grid into non-overlapping rectangles such that every rectangle contains one circle, and every cell belongs to one rectangle. The digit in the circle indicates the size of the rectangle (the number of cells). Digits do not repeat in rectangles.

Digits separated by an X sum to 10. Digits separated by a V sum to 5. Not all such X's or V's are shown. Additionally, all shown X's and V's lie on the boundary between two rectangles.