## Task
 In your favorite game, you must shoot a target with a water-gun to gain points. Each target can be worth a different amount of points. 
 
 You are guaranteed to hit every target that you try to hit. You cannot hit consecutive targets though because targets are only visible for one second (one at a time) and it takes you a full second to reload your water-gun after shooting (you start the game already loaded).

 Given an array `vals` with the order of each target's point value, determine the maximum number of points that you can win.

## Example
 For `vals = [1, 2, 3, 4]`, the result should be `6`.
 
 your optimal strategy would be to let the first one pass and shoot the second one with value 2 and the 4th one with value 4 thus:

 `vals[1](2) + vals[3](4) = 6`
 
 For `vals = [5, 5, 5, 5, 5]`, the result should be `15`.
 
 your optimal strategy would be to shoot the 1st, 3rd and 5th value:
 
 `5 + 5 + 5 = 15`
 
 You haven't shoot the 2nd, 4th value because you are reloading your water-gun after shooting other values.
 
 Note that the value can be zero or negative, don't shoot them ;-)
 
 For `vals = [0, 0, -1, -1]`, the result should be `0`.
 
 For `vals = [5, -2, -9, -4]`, the result should be `5`.
 
 Shoot the first one is enough.
 
## Input/Output


 - `[input]` integer array `vals`

  The point values (negative or non-negative) of the targets (in order of appearance).


 - `[output]` an integer

  The maximum number of points that you can score.

```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 target_game(values):\n    a = b = 0\n    for n in values:\n        a, b = b, max(a + n, b)\n    return max(a, b)'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'target_game'
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: 5354