description: A binary string is a string that consists of characters 0 and 1. A bi-table is a table that has exactly two rows of equal length, each being a binary string.
  
  Let \operatorname{MEX} of a bi-table be the smallest digit among 0, 1, or 2 that does not occur in the bi-table. For example, \operatorname{MEX} for \begin{bmatrix} 0011\\\ 1010 \end{bmatrix} is 2, because 0 and 1 occur in the bi-table at least once. \operatorname{MEX} for \begin{bmatrix} 111\\\ 111 \end{bmatrix} is 0, because 0 and 2 do not occur in the bi-table, and 0 < 2.
  
  You are given a bi-table with n columns. You should cut it into any number of bi-tables (each consisting of consecutive columns) so that each column is in exactly one bi-table. It is possible to cut the bi-table into a single bi-table — the whole bi-table.
  
  What is the maximal sum of \operatorname{MEX} of all resulting bi-tables can be?
  
  Input
  
  The input consists of multiple test cases. The first line contains a single integer t (1 ≤ t ≤ 10^4) — the number of test cases. Description of the test cases follows.
  
  The first line of the description of each test case contains a single integer n (1 ≤ n ≤ 10^5) — the number of columns in the bi-table.
  
  Each of the next two lines contains a binary string of length n — the rows of the bi-table.
  
  It's guaranteed that the sum of n over all test cases does not exceed 10^5.
  
  Output
  
  For each test case print a single integer — the maximal sum of \operatorname{MEX} of all bi-tables that it is possible to get by cutting the given bi-table optimally.
  
  Example
  
  Input
  
  
  4
  7
  0101000
  1101100
  5
  01100
  10101
  2
  01
  01
  6
  000000
  111111
  
  
  Output
  
  
  8
  8
  2
  12
  
  Note
  
  In the first test case you can cut the bi-table as follows:
  
    * \begin{bmatrix} 0\\\ 1 \end{bmatrix}, its \operatorname{MEX} is 2.
    * \begin{bmatrix} 10\\\ 10 \end{bmatrix}, its \operatorname{MEX} is 2.
    * \begin{bmatrix} 1\\\ 1 \end{bmatrix}, its \operatorname{MEX} is 0.
    * \begin{bmatrix} 0\\\ 1 \end{bmatrix}, its \operatorname{MEX} is 2.
    * \begin{bmatrix} 0\\\ 0 \end{bmatrix}, its \operatorname{MEX} is 1.
    * \begin{bmatrix} 0\\\ 0 \end{bmatrix}, its \operatorname{MEX} is 1.
  
  
  
  The sum of \operatorname{MEX} is 8.
solution: #----------FASTIOSTART-----------#
  from __future__ import division, print_function
  import os
  import sys
  from io import BytesIO, IOBase
  if sys.version_info[0] < 3:
  	from __builtin__ import xrange as range
  	from future_builtins import ascii, filter, hex, map, oct, zip
  BUFSIZE = 8192
  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):
  	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)
  input = lambda: sys.stdin.readline().rstrip("\r\n")
  #----------FASTIOFINISH----------#
  import collections,string,bisect,re,random,queue,itertools,statistics,math
  from collections import *
  from bisect import *
  from string import *
  from itertools import * 
  from statistics import *
  from math import *
  from re import *
  from queue import *
  #----------SASTA_STL-------------#
  # stack
  class Stack:
      def __init__(self):self.items = []
      def push(self, item):self.items.append(item)
      def pop(self):return self.items.pop()
      def empty(self):return self.items == []
      def size(self):return len(self.items)
      def at(self,idx):
      	try:return self.items[idx]
      	except:return -1
  #priority_queue
  class priority_queue(object):
      def __init__(self):self.queue = []
      def __str__(self):return ' '.join([str(i) for i in self.queue])
      def empty(self):return len(self.queue) == 0
      def push(self, data):self.queue.append(data)
      def pop(self):
          try:
              max = 0
              for i in range(len(self.queue)):
                  if self.queue[i] > self.queue[max]:
                      max = i
              item = self.queue[max]
              del self.queue[max]
              return item
          except IndexError:
              print()
              exit()
  #----------SASTA_STL-------------#
  mod  = int(1e9+7)
  imax = float("inf")
  imin = float("-inf")
  true = True
  false= False
  N 	 = int(1e5+10)
  none = None
  inp = lambda : input()
  I   = lambda : int(inp())
  M   = lambda : map(int,inp().split())
  MS  = lambda : map(str,inp().split())
  S   = lambda : list(MS())
  L   = lambda : list(M())
  def IO():
  	try:sys.stdin = open('input.txt', 'r');sys.stdout = open('uttar.txt', 'w')
  	except:pass
  IO()
  #----------TOTKA-----------#
  """
  def check(s,n,cc):
  	cnt=cc
  	for i in range(1,n):
  		if s[i]=="0":
  			if s[i-1]=="0":continue;
  			else:cnt+=1
  	return cnt;
  def B_(s,n):
  	# totka hai dosto !
  	cnt=1 if s[0]=="0" else 0
  	res=check(s,n,cnt)
  	return min(res,2)
  def dec(s):
  	return int(s,2)
  def subs(s,n):
  	new=[]
  	for i in range(n):
  		for j in range(i+1,n+1):
  			new.append(dec(s[i:j]))
  	return new"""
  
  
  def kabraji_ka_totka():
  	# totka hai dosto !
  	n=I()
  	res=0
  	found="2"
  	for i,j in zip(inp(),inp()):
  		if i!=j:
  			res+=2
  			found = "2"
  		else:
  			res+=(i=="0")
  			if i!=found and found != "2":
  				res+=1
  				found="2"
  
  			else:
  				found=i;
  	print(res)	
  
  #----------TOTKA----------#
  if __name__ == '__main__':
  	for i in range(I()):
  		#print("Case #"+(str(i+1))+": ")
  		kabraji_ka_totka()