Once N boys and M girls attended a party. You are given a matrix A of N rows and M columns where Aij is 1 if the i-th boy likes the j-th girl, otherwise it will be 0. Note that it is not necessary that if a boy x likes girl y, then girl y should like boy x.
You know that if there are two different boys x and y, who both like girl z, then there will be a collision.
Can you calculate the number of different collisions at this party? Note that order of boys in the collision doesn't matter.

-----Input-----
The first line contains a single integer T denoting the number of test cases. Then T test cases follow.
The first line of each test case contains two space separated integers N, M denoting the number of boys and girls, respectively.
Each of the following N lines contain M characters, each of them is either '0' or '1'.

-----Output-----
For each test case output a single line containing an integer corresponding to the number of collisions at the party.

-----Constraints-----
- 1 ≤ T ≤ 100
- 1 ≤ N, M ≤ 10

-----Example-----
Input:
2
4 3
111
100
110
000
2 2
10
01

Output:
4
0

-----Explanation-----
Example Case 1. All three boys like the first girl, so there are (1, 2, 1), (1, 3, 1), (2, 3, 1) collisions with her. Boys 1 and 3 both like the second girl so this is one more collision. Only one boy likes the third girl, so there are no collisions with her and thus we have 4 collisions total.
Example Case 2. For each girl there is only one boy who likes her, so there are no collisions at all.

```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

ns = {"__name__": "__main__"}
for _k, _v in list(globals().items()):
    if not _k.startswith("_"):
        ns[_k] = _v
_CODE = "t = int(input())\nfor _ in range(t):\n n, m = map(int, input().split())\n matrix = []\n for i in range(n):\n  matrix.append(list(input()))\n collision = 0\n for i in range(m):\n  count = 0\n  for j in range(n):\n   if matrix[j][i] == '1':\n    count += 1\n  # print('Count:', count)\n  if count > 1:\n   collision += ((count * (count-1)) // 2)\n print(collision)"
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

```

Measured memory_bytes: 13167