### Final version
Instead of strings I use the following node structure for storing items:
```zig
const SnailItem = union(enum) {
    num: u6,
    pair: *SnailNumber,
}
const SnailNumber = struct {
    left: ?SnailItem,
    right: ?SnailItem,
    parent: ?SnailNumber,
}
```

The first step is parsing the string to this, every other manipulation is done
on the `SnailNumber`. First part drops down to 10ms, second part is ~200ms.

more than 255k hits for chache items with my imput. Runs ~70ms on the rpi4.

more than 255k hits for chache items with my input. Runs ~70ms on the rpi4.

row/col state before changing them, but it is bearable.

row/col state before changing them, but it is bearable. Running time is ~250ms.

This way every coordinate is comes as Coord{ .x = value / grid_cols, .y = value
% grid_cols}. Might worth a try.

This way every coordinate is comes as `Coord{ .x = value / grid_cols, .y = value
% grid_cols}`. Might worth a try.