样例过了

#include<bits/stdc++.h>
using namespace std;
bool s=1;
int main(){
	int n;
	cin>>n;
	while(n--){
		bool p=1;
		string s1="";
		string a;
		int m;
		cin>>m;
		while(m--){
			cin>>a;
			for(int i=1;i<a.size();i++){
				if(a[i]<a[i-1])p=0;
			}
			if(s1[s1.size()-1]>a[0]){
				if(s1[0]>a[a.size()]-1){
					p=0;
				}else{
					string b=s1;
					s1=a+b;
				}
			}else{
				s1+=a;
			}
		}
		if(p){
			cout<<1<<endl;
		}else cout<<0<<endl;
	}
}