# Letterss of Natac
In a game I just made up that doesn’t have anything to do with any other game that you may or may not have played, you collect resources on each turn and then use those resources to build settlements, roads, and cities or buy a development. Other kata about this game can be found [here](https://www.codewars.com/collections/59e6938afc3c49005900011f).

## Task
This kata asks you to implement the function `build_or_buy(hand)` , which takes as input a `hand`, the resources you have (a string of letters representing the resources you have), and returns a list of the unique game objects you can build or buy given your hand. 

There are five different resources, `'b'`, `'w'`, `'g'`, `'s'`, and `'o'`.

Game objects and the resources required to build or buy them are as follows:
1. `'road'`: `bw`
2. `'settlement'`: `bwsg`
3. `'city'`: `ooogg`
4. `'development'`: `osg`

## Examples
```python
build_or_buy("bwoo")  => ['road']
build_or_buy("bwsg")  => ['road', 'settlement'] or ['settlement', 'road']
build_or_buy("")      => []
build_or_buy("ogogoogogo")  => ['city']

```

## Notes: 
1. Don't mutate the hand
2. The order of the returned list doesn't matter
3. You do not have to test for whether a hand is valid. 
4. The list will be interpreted to mean 'you can build any of these objects,' not 'you can build all these objects in one play'. See example 2 above, even though there is only one `'b'` and one `'w'` in `hand`, both `Road()` and `Settlement()` are in the list. 
5. A hand can be empty. In the event a hand is empty, you can't build or buy anything, so return an empty list, see example 3 above.
6. Hand are between 0 and 39 in length.

```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 = "from collections import Counter\n\ndef build_or_buy(hand):\n    res = []\n    bank = Counter(hand)\n    if bank['b'] > 0 and bank['w'] > 0:\n        res.append('road')\n        if bank['s'] > 0 and bank['g'] > 0:\n            res.append('settlement')\n    if bank['o'] > 2 and bank['g'] > 1:\n        res.append('city')\n    if bank['o'] > 0 and bank['s'] > 0 and bank['g'] > 0:\n        res.append('development')\n    return res"
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'build_or_buy'
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: 9886