#include<bits/stdc++.h>
using namespace std;
int read()
{
  int f=1,x=0;char c=getchar();
  while(!isdigit(c))
  {
    if(c=='-')  f=-1;
    c=getchar();
  }
  while(isdigit(c))
  {
    x=x*10+(c-'0');
    c=getchar();
  }
  return x*f;
}
int T,n,f1[100010],f2[100010];
int k1[100010][2],k2[100010][2];
struct nx
{
  int l,r;
}h1[100010],h2[100010];
string s1,s2,t1,t2;
int ans;
void inti()
{
  n=read();
  cin>>s1>>s2>>t1>>t2;
  s1="*"+s1,s2="*"+s2;
  t1="*"+t1,t2="*"+t2;
  for(int i=1;i<=n;i++)
  {
    f1[i]=t1[i]-'0';
    f2[i]=t2[i]-'0';
    if(t1[i-1]=='0'&&!t1[i+1])
      f1[i]=0;
    if(t2[i-1]=='0'&&!t2[i+1])
      f2[i]=0;
  }
  if(t1[n-1]=='0')
    f1[n]=0;
  if(t2[n-1]=='0')
    f2[n]=0;
  if(t1[2]=='0')
    f1[1]=0;
  if(t2[2]=='0')
    f2[1]=0;
  for(int i=1;i<=n;i++)
  {
    k1[i][0]=k1[i-1][0],k1[i][1]=k1[i-1][1];
    k2[i][0]=k2[i-1][0],k2[i][1]=k2[i-1][1];
    if(f1[i])
      k1[i][s1[i]-'0']+=1;
    if(f2[i])
      k2[i][s2[i]-'0']+=1;
  }
  int x1l=0,x2l=0,x1r=0,x2r=0;
  while(x1r<n)
  {
    if(f1[x1r+1])
    {
      x1l=x1r+1;
      while(f1[x1r+1]&&x1r+1<=n)
        x1r++;
      for(int i=x1l;i<=x1r;i++)
        h1[i].l=x1l,h1[i].r=x1r;
    }
    while(!f1[x1r+1])
      x1r++;
  }
  while(x2r<n)
  {
    if(f2[x2r+1])
    {
      x2l=x2r+1;
      while(f2[x2r+1]&&x2r+1<=n)
        x2r++;
      for(int i=x2l;i<=x2r;i++)
        h2[i].l=x2l,h2[i].r=x2r;
    }
    while(!f2[x2r+1])
      x2r++;
  }
}
int main()
{
  freopen("edit.in","r",stdin);
  freopen("edit.out","w",stdout);
  T=read();
  while(T--)
  {
    inti();
    for(int i=1;i<=n;i++)
    {
      if(!f1[i]&&!f2[i]&&s1[i]==s2[i])
          ans++;
      else  if(!f1[i]&&f2[i]&&k2[h2[i].r][s1[i]-'0']-k2[h2[i].l-1][s1[i]-'0']>0)
        ans++,k2[h2[i].l-1][s1[i]-'0']+=1;
      else  if(f1[i]&&!f2[i]&&k1[h1[i].r][s2[i]-'0']-k1[h1[i].l-1][s2[i]-'0']>0)
        ans++,k1[h1[i].l-1][s2[i]-'0']+=1;
      else  if(f1[i]&&f2[i])
      {
        if(k2[h2[i].r][0]-k2[h2[i].l-1][0]>0&&k1[h1[i].r][0]-k1[h1[i].l-1][0]>0)
          ans++,k2[h2[i].l-1][0]+=1,k1[h1[i].l-1][0]+=1;
        else if(k2[h2[i].r][1]-k2[h2[i].l-1][1]>0&&k1[h1[i].r][1]-k1[h1[i].l-1][1]>0)
          ans++,k2[h2[i].l-1][1]+=1,k1[h1[i].l-1][1]+=1;
      }
    }
    printf("%d\n",ans);
    ans=0;
    for(int i=1;i<=n;i++)
      f1[i]=f2[i]=h1[i].l=h1[i].r=h2[i].l=h2[i].r=0;
  }
  return 0;
}