Logic Masters Deutschland e.V.

Place the digits 1 through 9 once into each row, column, and box. The clues outside the grid are sandwich-sum clues; each number clue gives the sum of the digits between (but not including) the 1 and the 9 in the indicated row or column. The "?" clues are sandwiches with non-zero sums; they may or may not have the same value.

A sequence of orthogonally or diagonally adjacent cells (the "snake") connects the two circled digits, and contains consecutive Fibonacci numbers, starting with the first 1. Numbers with multiple digits are written along the snake starting with the highest place value. Non-consecutive snake cells may not touch orthogonally or diagonally, but the snake is allowed to make orthogonal 90-degree turns (e.g. R2C5 -> R1C5 -> R1C6).

Also, the snake has been sampling your sandwich fillings! In each given sandwich, including the "?" ones, exactly one of the digits between the 1 and 9 is a snake cell. (The 1s and 9s delimiting the sandwiches may or may not be snake cells as well.)

Online solvers: CTC, f-puzzles (note that the f-puzzles conflict checker doesn't like the "?" clues)