Logic Masters Deutschland e.V.

Hello, here is a puzzle with quiet long rules... However, they are not complicated, contrarily to the puzzle (I hope...)

penpa link: https://git.io/JGVKY

Rules:

Normal sudoku - antiknight - sandwich

antiknight: identical numbers can not be a knight's move apart (in chess)

sandwich: numbers outside the grid indicate the sum of the numbers sandwiched between the 1 and 9 in the corresponding row/column.

In addition, a 1-cell wide closed loop that can't touch itself (even diagonally) represents a horse obstacle course. Given sandwich clues indicate ALL the rows/columns containing an obstacle. An obstacle is the cells sandwiched between the 1 and 9 in that row/column. The path must pass over all obstacles exactly once, and cannot turn over the obstacle. It cannot contain any 1s or 9s (even if they are not part of an obstacle). A negative constraint apply, i.e. the path cannot correctly pass over an obstacle in a row/col without a sandwich clue.

Green squares can't be on the path and indicate how many neighboring cells are part of the path (orthogonally and diagonally). Their value is indicated in the cell corner.

X value must be found by the solver.