The prime numbers are not regularly spaced. For example from `2` to `3` the step is `1`.
From `3` to `5` the step is `2`. From `7` to `11` it is `4`.
Between 2 and 50 we have the following pairs of 2-steps primes:

`3, 5 - 5, 7, - 11, 13, - 17, 19, - 29, 31, - 41, 43`

We will write a function `step` with parameters:

- `g` (integer >= 2) which indicates the step we are looking for,

- `m` (integer >= 2) which gives the start of the search (m inclusive),

- `n` (integer >= m) which gives the end of the search (n inclusive)

In the example above `step(2, 2, 50)` will return `[3, 5]` which is the first pair between 2 and 50 with a 2-steps.

So this function should return the **first** pair of the two prime numbers spaced with a step of `g`
between the limits `m`, `n` if these g-steps prime numbers exist otherwise `nil` or `null` or `None` or `Nothing` or `[]` or `"0, 0"` or `{0, 0}` or `0 0`(depending on the language). 


#Examples:

- 


`step(2, 5, 7) --> [5, 7] or (5, 7) or {5, 7} or "5 7"`

`step(2, 5, 5) --> nil or ... or [] in Ocaml or {0, 0} in C++`

`step(4, 130, 200) --> [163, 167] or (163, 167) or {163, 167}`

- **See more examples for your language in "RUN"**


- Remarks:

([193, 197] is also such a 4-steps primes between 130 and 200 but it's not the first pair).

`step(6, 100, 110) --> [101, 107]` though there is a prime between 101 and 107 which is 103; the pair 101-103 is a 2-step.


#Notes: 
The idea of "step" is close to that of "gap" but it is not exactly the same. For those interested they can have a look
at . 

A "gap" is more restrictive: there must be no primes in between 
(101-107 is a "step" but not a "gap". Next kata will be about "gaps":-).

For Go: nil slice is expected when there are no `step` between m and n.
Example: step(2,4900,4919) --> nil

```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 step(g, m, n):\n    return next(([a, a+g] for a in range(m, n-g+1) if is_prime(a) and is_prime(a+g)), None)\n\n\ndef is_prime(n):\n    factors = 0\n    for k in (2, 3):\n        while n % k == 0 and factors < 2:\n            n //= k\n            factors += 1\n    k = 5\n    step = 2\n    while k * k <= n and factors < 2:\n        if n % k:\n            k += step\n            step = 6 - step\n        else:\n            n //= k\n            factors += 1\n    if n > 1:\n        factors += 1\n    return factors == 1\n'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'step'
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: 6122