# Task
 Your task is to find the similarity of given sorted arrays `a` and `b`, which is defined as follows: 
 
 you take the number of elements which are present in both arrays and divide it by the number of elements which are present in at least one array.

 It also can be written as a formula `similarity(A, B) = #(A ∩ B) / #(A ∪ B)`, where `#(C)` is the number of elements in C, `∩` is intersection of arrays, `∪` is union of arrays.

 This is known as `Jaccard similarity`.

 The result is guaranteed to fit any floating-point type without rounding.

# Example

 For `a = [1, 2, 4, 6, 7]` and `b = [2, 3, 4, 7]`:
```
elements [2, 4, 7] are present in both arrays;
elements [1, 2, 3, 4, 6, 7] are present in at least one of the arrays.
So the similarity equals to 3 / 6 = 0.5.```

# Input/Output


 - `[input]` integer array `a`

  A `sorted` array of positive integers. 
  
  All elements are `different` and are `less than 100`.
  
  `1 ≤ a.length ≤ 100`


 - `[input]` integer array `b`

  An array in the same format as `a`.


 - `[output]` a float number

  The similarity of the arrays.
  
  ```Haskell
  
  In Haskell the two arrays are passed as a touple.
  ```

```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 similarity(a, b):\n    sa, sb = set(a), set(b)\n    return len(sa & sb) / len(sa | sb)'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'similarity'
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: 5676