Problem: Pink Floyd are pulling a prank on Roger Waters. They know he doesn't like [walls](https://www.youtube.com/watch?v=YR5ApYxkU-U), he wants to be able to walk freely, so they are blocking him from exiting his room which can be seen as a grid.

Roger Waters has a square grid of size n× n and he wants to traverse his grid from the upper left (1,1) corner to the lower right corner (n,n). Waters can move from a square to any other square adjacent by a side, as long as he is still in the grid. Also except for the cells (1,1) and (n,n) every cell has a value 0 or 1 in it.

Before starting his traversal he will pick either a 0 or a 1 and will be able to only go to cells values in which are equal to the digit he chose. The starting and finishing cells (1,1) and (n,n) are exempt from this rule, he may go through them regardless of picked digit. Because of this the cell (1,1) takes value the letter 'S' and the cell (n,n) takes value the letter 'F'.

For example, in the first example test case, he can go from (1, 1) to (n, n) by using the zeroes on this path: (1, 1), (2, 1), (2, 2), (2, 3), (3, 3), (3, 4), (4, 4)

The rest of the band (Pink Floyd) wants Waters to not be able to do his traversal, so while he is not looking they will invert at most two cells in the grid (from 0 to 1 or vice versa). They are afraid they will not be quick enough and asked for your help in choosing the cells.  Note that you cannot invert cells (1, 1) and (n, n).

We can show that there always exists a solution for the given constraints.

Also note that Waters will pick his digit of the traversal after the band has changed his grid, so he must not be able to reach (n,n) no matter what digit he picks.

Input

Each test contains multiple test cases. The first line contains the number of test cases t (1 ≤ t ≤ 50). Description of the test cases follows.

The first line of each test case contains one integers n (3 ≤ n ≤ 200).

The following n lines of each test case contain the binary grid, square (1, 1) being colored in 'S' and square (n, n) being colored in 'F'.

The sum of values of n doesn't exceed 200.

Output

For each test case output on the first line an integer c (0 ≤ c ≤ 2) — the number of inverted cells.

In i-th of the following c lines, print the coordinates of the i-th cell you inverted. You may not invert the same cell twice.  Note that you cannot invert cells (1, 1) and (n, n).

Example

Input


3
4
S010
0001
1000
111F
3
S10
101
01F
5
S0101
00000
01111
11111
0001F


Output


1
3 4
2
1 2
2 1
0

Note

For the first test case, after inverting the cell, we get the following grid:
    
    
      
    S010  
    0001  
    1001  
    111F  
    

Solution (in PYTHON3):

Solution:
# ===============================================================================================
# importing some useful libraries.
from __future__ import division, print_function
from fractions import Fraction
import sys
import os
from io import BytesIO, IOBase
from itertools import *
import bisect
from heapq import *
from math import ceil, floor
from copy import *
from collections import deque, defaultdict
from collections import Counter as counter  # Counter(list)  return a dict with {key: count}
from itertools import combinations  # if a = [1,2,3] then print(list(comb(a,2))) -----> [(1, 2), (1, 3), (2, 3)]
from itertools import permutations as permutate
from bisect import bisect_left as bl
from operator import *
# If the element is already present in the list,

# the left most position where element has to be inserted is returned.
from bisect import bisect_right as br
from bisect import bisect

# If the element is already present in the list,
# the right most position where element has to be inserted is returned

# ==============================================================================================
# fast I/O region

BUFSIZE = 8192
from sys import stderr


class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")


def print(*args, **kwargs):
    """Prints the values to a stream, or to sys.stdout by default."""
    sep, file = kwargs.pop("sep", " "), kwargs.pop("file", sys.stdout)
    at_start = True
    for x in args:
        if not at_start:
            file.write(sep)
        file.write(str(x))
        at_start = False
    file.write(kwargs.pop("end", "\n"))
    if kwargs.pop("flush", False):
        file.flush()


if sys.version_info[0] < 3:
    sys.stdin, sys.stdout = FastIO(sys.stdin), FastIO(sys.stdout)
else:
    sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)

# inp = lambda: sys.stdin.readline().rstrip("\r\n")

# ===============================================================================================
### START ITERATE RECURSION ###
from types import GeneratorType


def iterative(f, stack=[]):
    print(stack)

    def wrapped_func(*args, **kwargs):
        if stack: return f(*args, **kwargs)
        to = f(*args, **kwargs)
        while True:
            if type(to) is GeneratorType:
                stack.append(to)
                to = next(to)
                continue
            stack.pop()
            if not stack: break
            to = stack[-1].send(to)
        return to

    return wrapped_func


#### END ITERATE RECURSION ####

# ===============================================================================================
# some shortcuts

mod = 1000000007


def inp(): return sys.stdin.readline().rstrip("\r\n")  # for fast input


def out(var): sys.stdout.write(str(var))  # for fast output, always take string


def lis(): return list(map(int, inp().split()))


def stringlis(): return list(map(str, inp().split()))


def sep(): return map(int, inp().split())


def strsep(): return map(str, inp().split())


def fsep(): return map(float, inp().split())


def nextline(): out("\n")  # as stdout.write always print sring.


def testcase(t):
    for p in range(t):
        solve()


def pow(x, y, p):
    res = 1  # Initialize result
    x = x % p  # Update x if it is more , than or equal to p
    if (x == 0):
        return 0
    while (y > 0):
        if ((y & 1) == 1):  # If y is odd, multiply, x with result
            res = (res * x) % p

        y = y >> 1  # y = y/2
        x = (x * x) % p
    return res


from functools import reduce


def factors(n):
    return set(reduce(list.__add__,
                      ([i, n // i] for i in range(1, int(n ** 0.5) + 1) if n % i == 0)))


def gcd(a, b):
    if a == b: return a
    while b > 0: a, b = b, a % b
    return a


# discrete binary search
# minimise:
# def search():
#     l = 0
#     r = 10 ** 15
#
#     for i in range(200):
#         if isvalid(l):
#             return l
#         if l == r:
#             return l
#         m = (l + r) // 2
#         if isvalid(m) and not isvalid(m - 1):
#             return m
#         if isvalid(m):
#             r = m + 1
#         else:
#             l = m
#     return m

# maximise:
# def search():
#     l = 0
#     r = 10 ** 15
#
#     for i in range(200):
#         # print(l,r)
#         if isvalid(r):
#             return r
#         if l == r:
#             return l
#         m = (l + r) // 2
#         if isvalid(m) and not isvalid(m + 1):
#             return m
#         if isvalid(m):
#             l = m
#         else:
#             r = m - 1
#     return m


##to find factorial and ncr
# N=100000
# mod = 10**9 +7
# fac = [1, 1]
# finv = [1, 1]
# inv = [0, 1]
#
# for i in range(2, N + 1):
#     fac.append((fac[-1] * i) % mod)
#     inv.append(mod - (inv[mod % i] * (mod // i) % mod))
#     finv.append(finv[-1] * inv[-1] % mod)
#
#
# def comb(n, r):
#     if n < r:
#         return 0
#     else:
#         return fac[n] * (finv[r] * finv[n - r] % mod) % mod


##############Find sum of product of subsets of size k in a array
# ar=[0,1,2,3]
# k=3
# n=len(ar)-1
# dp=[0]*(n+1)
# dp[0]=1
# for pos in range(1,n+1):
#     dp[pos]=0
#     l=max(1,k+pos-n-1)
#     for j in range(min(pos,k),l-1,-1):
#         dp[j]=dp[j]+ar[pos]*dp[j-1]
# print(dp[k])

def prefix_sum(ar):  # [1,2,3,4]->[1,3,6,10]
    return list(accumulate(ar))


def suffix_sum(ar):  # [1,2,3,4]->[10,9,7,4]
    return list(accumulate(ar[::-1]))[::-1]


def N():
    return int(inp())


# =========================================================================================
from collections import defaultdict


def numberOfSetBits(i):
    i = i - ((i >> 1) & 0x55555555)
    i = (i & 0x33333333) + ((i >> 2) & 0x33333333)
    return (((i + (i >> 4) & 0xF0F0F0F) * 0x1010101) & 0xffffffff) >> 24


def solve():
    n=N()
    ar=[inp() for _ in range(n)]
    c=0
    ans=[]
    if ar[0][1]==ar[1][0]:
        t=ar[0][1]
        if ar[n-1][n-2]==t:
            c+=1
            ans.append((n,n-1))
        if ar[n-2][n-1]==t:
            c+=1
            ans.append((n-1,n))
        print(c)
        for i in ans:
            print(*i)
        return
    if ar[n-1][n-2]==ar[n-2][n-1]:
        t=ar[n-1][n-2]
        if ar[0][1]==t:
            c+=1
            ans.append((1,2))
        if ar[1][0]==t:
            c+=1
            ans.append((2,1))
        print(c)
        for i in ans:
            print(*i)
        return
    if ar[1][0]!="0":
        c+=1
        ans.append((2,1))
    if ar[0][1]!="0":
        c+=1
        ans.append((1,2))
    if ar[n-1][n-2]!="1":
        c+=1
        ans.append((n,n-1))
    if ar[n-2][n-1]!="1":
        c+=1
        ans.append((n-1,n))
    print(c)
    for i in ans:
        print(*i)
    return





# solve()
testcase(int(inp()))