//#pragma GCC optimize(1,2,3,"Ofast","inline")
#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
#define int long long
#define fre freopen(".in","r",stdin),freopen(".out","w",stdout)
#define fcl fclose(stdin),fclose(stdout)
inline int read() {
	register int x=0,m=1;
	register char ch=getchar();
	while(!isdigit(ch)) {
		if(ch=='-') m=-1;
		ch=getchar();
	}
	while(isdigit(ch)) {
		x=(x<<1)+(x<<3)+(ch^48);
		ch=getchar();
	}
	return x*m;
}
inline void write(int x) {
	if(x<0) putchar('-'),write(-x);
	else {
		if(x>=10) write(x/10);
		putchar(x%10+'0');
	}
}
#define read(n) n=read()
int T,n;
string a;
signed main() {
//	fre;
	read(T);
	while(T--) {
		read(n);
		cin>>a;
		string res="";
		int x=0;
		for(register int i=n-1;~i;--i)
			if(a[i]=='0') {
				x=a[i-2]^48;
				x=(x<<1)+(x<<3)+(a[i-1]^48);
				res=char(x-1+'a')+res;
				i-=2;
			} else
				res=char((a[i]^48)-1+'a')+res;
		cout<<res<<endl;
	}
//	fcl;
	return 0;
}



#include <iostream>
#include <cstring>
#include <algorithm>
#include <cmath>
using namespace std;
#define int long long
inline int read() {
	int x=0,m=1;
	char ch=getchar();
	while(!isdigit(ch)) {
		if(ch=='-') m=-1;
		ch=getchar();
	}
	while(isdigit(ch)) {
		x=(x<<1)+(x<<3)+(ch^48);
		ch=getchar();
	}
	return x*m;
}
inline void write(int x) {
	if(x<0) putchar('-'),write(-x);
	else {

		if(x>=10) write(x/10);
		putchar(x%10+'0');
	}
}
#define read(n) n=read()
const int N=105;
int n,T,a[N],b[N];
signed main() {
	read(T);
	while(T--) {
		read(n);
		int cnt=0,res=0;
		for(register int i=1;i<=n;++i) {
			read(a[i]);
			if(a[i]==1)
				++res;
		}
		for(register int i=1;i<=n;++i) {
			read(b[i]);
			if(a[i]!=b[i])
				++cnt;
			if(b[i]==1)
				--res;
		}
		if(cnt==0) {
			write(cnt),putchar('\n');
			continue;
		}
		int ans=abs(res);
		if(ans!=cnt) ++ans;
		write(ans),putchar('\n');
	}
	return 0;
}