#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define MAXN 100010
inline ll read(){
    ll x=0;
    char c=getchar();
    while(c<'0'||c>'9')c=getchar();
    while(c>='0'&&c<='9'){
        x=x*10+c-'0';
        c=getchar();
    }
    return x;
}
char c1[MAXN],c2[MAXN],type1[MAXN],type2[MAXN];
ll n,T; 
int main(){
    freopen("edit.in","r",stdin);
    freopen("edit.out","w",stdout);
    cin>>T;
    while(T--){
        cin>>n;
        cin>>(c1+1)>>(c2+1)>>(type1+1)>>(type2+1);
        ll ans=0;
        for(int i=1;i<=n;i++)if(c1[i]==c2[i])ans++;
        cout<<ans<<endl;
    }
    return 0;
}