Logic Masters Deutschland e.V.

Normal sudoku rules apply: Fill the grid with digits from 1 to 9, so that every row, column, and 3x3 box contains each of the 9 digits exactly once.

In addition, there is a mountain hidden in the grid. Its peak is at the 9 in the central box. The mountain consists of all cells which can be reached from the peak by repeatedly moving from a cell to an orthogonally adjacent cell containing a smaller digit. (See example below.)

Each clue outside the grid shows the sum of the mountain cells between the 1 and the 9 in the clue's row or column. (It doesn't matter if the 1 and/or 9 are in the mountain.)

You can solve this in Penpa or in the CTC-app.

As an example of the mountain definition, in the grid below the mountain is shaded, a path is drawn in red from the peak to another mountain cell, and the mountain sandwich sums are shown.

If you want to solve an easier puzzle of this type first, try Introduction to mountain sudoku. And if you like this puzzle, you might also like my other mountain sudokus.