#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
int main()
{
int t;
cin>>t;
while(t--)
{
bool hor=0;
int n;
cin>>n;
vector<string>a(2);
cin>>a[0];
cin>>a[1];
int c=0;
int cn1=0,cn2=0;
cn1=count(a[0].begin(),a[0].end(),'*');
cn2=count(a[1].begin(),a[1].end(),'*');
if(cn1==0)
{
bool flag=0;
for(int i=0;i<n;i++)
{
if(a[1][i]=='*'&&flag==0)
{
flag=1;
}
else if(a[1][i]=='*'&&flag==1)
{
c++;
}
}
cout<<c<<endl;
continue;
}
else if(cn2==0)
{
bool flag=0;
for(int i=0;i<n;i++)
{
if(a[0][i]=='*'&&flag==0)
{
flag=1;
}
else if(a[0][i]=='*'&&flag==1)
{
c++;
}
}
cout<<c<<endl;
continue;
}
else
{
bool flag=0;
int m=-1,t=-1;
for(int i=0;i<n;i++)
{
if(a[0][i]=='*'&&m==-1)
{
if(t==-1)
{
m=i;
continue;
}
}
if(a[1][i]=='*'&&t==-1)
{
if(m==-1)
{
t=i;
continue;
}
}
if((m>t)&&a[0][i]=='*')
{
c++;
m=i;
if(a[1][i]=='*')
t=i;
continue;
}
if(t>m&&a[0][i]=='*')
{
m=i;
if(a[1][i]=='*')
t=i;
continue;
}
if((m>t)&&a[1][i]=='*')
{
t=i;
continue;
}
if(t>m&&a[1][i]=='*')
{
c++;
t=i;
continue;
}
else if(m==t&&(a[0][i]=='*'||a[1][i]=='*'))
{
c++;
if(a[0][i]=='*')
m=i;
if(a[1][i]=='*')
t=i;
}
}
/*if(flagg==1&&a[1][i]=='*')
flagg1=1;
if(flag1==1||flagg1==1)
c++;
flag1=0;flagg1=0;*/
cout<<c+1<<endl;
continue;
}
/*else
{
bool flag=0;
int m=-1,t=-1;
for(int i=0;i<n;i++)
{
if(a[0][i]=='*'&&m==-1)
{
m=i;
continue;
}
if(a[1][i]=='*'&&t==-1)
{
t=i;
continue;
}
if((m>t)&&a[0][i]=='*')
{
c++;
m=i;
}
else if(t>m&&a[0][i]=='*')
{
m=i;
continue;
}
else if((m>t)&&a[1][i]=='*')
{
t=i;
continue;
}
else if(t>m&&a[1][i]=='*')
{
c++;
t=i;
}
}
if(flagg==1&&a[1][i]=='*')
flagg1=1;
if(flag1==1||flagg1==1)
c++;
flag1=0;flagg1=0;
cout<<c+1<<endl;
continue;*/
}
}
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