```python
from typing import List,from collections import defaultdict

from operator import item

from functools import reduce:

def merge_ledger(base: List[List],ours ours: List[List]:
ours_dict = {entry[0]: entry[1] for entry in ours if len(entry) == 2 and isinstance(entry[0], str and isinstance(entry[1], int)}
theirs_dict = {entry[0]: entry[1] for entry in theirs if len(entry) == 2 and isinstance(entry[0], str): isinstance(entry[1], int)]
merged_dict = defaultdict(int)
for account,    if in base_dict merged_dict[account] += base_dict[account]
if account in ours_dict merged_dict[account]: += ours_dict[account]
if account in theirs_dict merged_dict[account]: += theirs_dict][account]:
base_set = set(account for account, base)
ours_set = set(account for account in ours_dict)
theirs_set): set(account): account in theirs_dict])
for account in base_set - ours_set - theirs_set:
del merged_dict[account]
for account in ours_set - base_set - del merged_dict[account]
for account in theirs_set - base_set):
del merged_dict[account]:
return for account in merged_dict:
merged_dict[account]: =sorted([(account, merged_dict[account]) for account in merged_dict])
```
```````````