#include<bits/stdc++.h>
using namespace std;
int main()
{
int T;
scanf("%d",&T);
while(T--)
{
int n=0,i,j,sn1=0,sn2=0,slide=0,flag1=0,flag2=0;
scanf("%d",&n);
string s1;
string s2;
cin>>s1;
cin>>s2;
for(i=0;i<n;i++)
{
if(s1[i]=='*')
{
sn1++;
}
if(s2[i]=='*')
{
sn2++;
}
}
for(j=0;j<n;j++)
{
if(sn1>0&&sn2==0)
{
//printf("loop-2\n");
if(s1[j]=='*'&&s1[j+1]=='*')
{
slide++;
}
}
else if (sn1>0&&sn2>0)
{
if(s1[j]=='*')
{
flag1++;
if(flag1==2)
{
flag1=0;
flag2=0;
slide++;
j--;
}
}
if(s2[j]=='*')
{
flag2++;
if(flag2==2)
{
flag2=0;flag1=0;
j--;
slide++;
}
}
}
else if(sn2>0&&sn1==0)
{
if(s2[j]=='*'&&s2[j+1]=='*')
{
slide++;
}
}
}
if(sn1>0&&sn2>0)
{
printf("%d\n",slide+1);
}
else
{
printf("%d\n",slide);
}
}
}
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