## The galactic games have begun!

It's the galactic games! Beings of all worlds come together to compete in several interesting sports, like nroogring, fredling and buzzing (the beefolks love the last one). However, there's also the traditional marathon run.

Unfortunately, there have been cheaters in the last years, and the committee decided to place sensors on the track. Committees being committees, they've come up with the following rule:

> A sensor should be placed every 3 and 5 meters from the start, e.g.
> at 3m, 5m, 6m, 9m, 10m, 12m, 15m, 18m….

Since you're responsible for the track, you need to buy those sensors. Even worse, you don't know how long the track will be! And since there might be more than a single track, and you can't be bothered to do all of this by hand, you decide to write a program instead.

## Task
Return the sum of the multiples of 3 and 5 __below__ a number. Being the _galactic_ games, the tracks can get rather large, so your solution should work for _really_ large numbers (greater than 1,000,000).

### Examples
```python
solution (10) # => 23 = 3 + 5 + 6 + 9
solution (20) # => 78 = 3 + 5 + 6 + 9 + 10 + 12 + 15 + 18
```

```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 solution(number):\n    a = (number - 1) // 5\n    b = (number - 1) // 3\n    c = (number - 1) // 15\n    \n    sum_a = ((a * (a + 1)) // 2) * 5\n    sum_b = ((b * (b + 1)) // 2) * 3\n    sum_c = ((c * (c + 1)) // 2) * 15\n    \n    return sum_a + sum_b - sum_c'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'solution'
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: 5410