def grid_row_append(g: list[list[int]], i: int) -> int:
# append on a list-of-list subscript receiver: g[i].push(...).
g[i].append(99)
return len(g[i])
def first_row_total(g: list[list[int]]) -> int:
g[0].append(10)
g[0].append(20)
return sum(g[0])
def bucket_append(d: dict[str, list[int]], k: str, v: int) -> int:
# append on a dict-of-list subscript receiver: d.get_mut(&k).unwrap().push(v).
d[k].append(v)
return len(d[k])