Let us begin with an example:

A man has a rather old car being worth $2000. 
He saw a secondhand car being worth $8000. He wants to keep his old car until he can buy the secondhand one.

He thinks he can save $1000 each month but the prices of his old 
car and of the new one decrease of 1.5 percent per month.
Furthermore this percent of loss increases of `0.5` percent 
at the end of every two months.
Our man finds it difficult to make all these calculations.

**Can you help him?**

How many months will it take him to save up enough money to buy the car he wants, and how much money will he have left over?

**Parameters and return of function:**
```
parameter (positive int or float, guaranteed) startPriceOld (Old car price)
parameter (positive int or float, guaranteed) startPriceNew (New car price)
parameter (positive int or float, guaranteed) savingperMonth 
parameter (positive float or int, guaranteed) percentLossByMonth

nbMonths(2000, 8000, 1000, 1.5) should return [6, 766] or (6, 766)
```
###  Detail of the above example:
```
end month 1: percentLoss 1.5 available -4910.0
end month 2: percentLoss 2.0 available -3791.7999...
end month 3: percentLoss 2.0 available -2675.964
end month 4: percentLoss 2.5 available -1534.06489...
end month 5: percentLoss 2.5 available -395.71327...
end month 6: percentLoss 3.0 available 766.158120825...
return [6, 766] or (6, 766)

```

where `6` is the number of months at **the end of which** he can buy the new car and `766` is the nearest integer to `766.158...` (rounding `766.158` gives `766`).

**Note:** 

Selling, buying and saving are normally done at end of month.
Calculations are processed at the end of each considered month
but if, by chance from the start, the value of the old car is bigger than the value of the new one or equal there is no saving to be made, no need to wait so he can at the beginning of the month buy the new car:
```
nbMonths(12000, 8000, 1000, 1.5) should return [0, 4000]
nbMonths(8000, 8000, 1000, 1.5) should return [0, 0]
```

We don't take care of a deposit of savings in a bank:-)

```python

USER_FILENAME = "<user_code>"
import sys, json, builtins
import math, heapq, bisect, itertools, functools, collections, statistics, fractions, decimal, operator, array, random, re, string, os, pathlib
try:
    import resource as _res
except Exception:
    _res = None
from collections import Counter, defaultdict, deque, OrderedDict
from functools import lru_cache, reduce
from itertools import accumulate, permutations, combinations, product
from math import gcd, ceil, floor, sqrt
from decimal import Decimal
try:
    from typing import *
except Exception:
    pass
try:
    sys.setrecursionlimit(1_000_000)
except Exception:
    pass
try:
    import site as _site
    try:
        _sys_sites = _site.getsitepackages() if hasattr(_site, "getsitepackages") else []
        for _p in _sys_sites:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
    try:
        _usp = _site.getusersitepackages()
        if isinstance(_usp, str):
            _usp = [_usp]
        for _p in _usp:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
except Exception:
    pass

def _disabled_input(*args, **kwargs):
    raise RuntimeError("input() is disabled in callable mode")
builtins.input = _disabled_input

ns = {"__name__": "__judge__"}  # prevent if __name__ == "__main__" blocks
for _k, _v in list(globals().items()):
    if not _k.startswith("_"):
        ns[_k] = _v
_CODE = 'def nbMonths(startPriceOld, startPriceNew, savingperMonth, percentLossByMonth):\n    months_elapsed = 0\n    if startPriceOld >= startPriceNew:\n        return [months_elapsed, startPriceOld - startPriceNew]\n    \n    too_poor = True\n    while too_poor:\n        months_elapsed += 1\n        \n        if months_elapsed % 2 == 0:\n            percentLossByMonth += 0.5\n        \n        startPriceOld = startPriceOld * (1 - (percentLossByMonth / 100))\n        startPriceNew = startPriceNew * (1 - (percentLossByMonth / 100))      \n        available_funds = (startPriceOld + (savingperMonth * months_elapsed))\n        \n        if available_funds >= startPriceNew:\n            too_poor = False\n        \n    return [months_elapsed, int(round(available_funds - startPriceNew))]\n\n        \n        \n    \n        \n\n'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'nbMonths'
if _fn_name:
    if "Solution" in ns:
        try:
            _obj = ns["Solution"]()
            if hasattr(_obj, _fn_name):
                _target = getattr(_obj, _fn_name)
        except Exception:
            _target = None
    if _target is None and _fn_name in ns and callable(ns[_fn_name]):
        _target = ns[_fn_name]
# Fallback: if there's exactly one user-defined function, use it
if _target is None:
    _cands = [v for k, v in ns.items() if callable(v) and getattr(v, "__module__", "") in ("__judge__", "__main__")]
    _user_funcs = [c for c in _cands if getattr(c, "__name__", "").startswith("_") is False]
    if len(_user_funcs) == 1:
        _target = _user_funcs[0]
if _target is None:
    raise RuntimeError(f"Could not resolve callable '{_fn_name}'")

_raw = sys.stdin.read().strip()
if _raw:
    _parsed = json.loads(_raw)
    if isinstance(_parsed, dict):
        _kwargs = _parsed.get("kwargs", {})
        _args = _parsed.get("args", [])
    else:
        _args, _kwargs = _parsed, {}
else:
    _args, _kwargs = [], {}
if not isinstance(_args, (list, tuple)):
    _args = [_args]
_res = _target(*_args, **_kwargs)
try:
    sys.stdout.write(repr(_res) + "\n")
except Exception:
    pass

```

Measured memory_bytes: 5804