1 #include<iostream>
 2 #include<cstring>
 3 #include<cstdlib>
 4 #include<cstdio>
 5 #include<algorithm>
 6 #include<cmath>
 7 #include<queue>
 8 #include<map>
 9 #include<set>
10 #include<stack>
11 #include<string>
12 
13 #define N 20005
14 #define M 205
15 #define mod 10000007
16 //#define p 10000007
17 #define mod2 1000000000
18 #define ll long long
19 #define LL long long
20 #define eps 1e-6
21 #define inf 100000000
22 #define maxi(a,b) (a)>(b)? (a) : (b)
23 #define mini(a,b) (a)<(b)? (a) : (b)
24 
25 using namespace std;
26 
27 int n;
28 int T;
29 map<ll,bool>mp;
30 int flag;
31 
32 void ini()
33 {
34     flag=1;
35     scanf("%d",&n);
36     mp.clear();
37     char s[105];
38     int l;
39     int i;
40     queue<ll>q;
41     ll tt=1;
42     while(n--){
43         scanf("%s",s);
44         l=strlen(s);
45         tt=1;
46         for(i=0;i<l;i++){
47             tt=tt*10+s[i]-‘0‘;
48         }
49         q.push(tt);
50         mp[tt]=true;
51     }
52     ll te;
53     while(q.size()>=1){
54         te=q.front();
55         q.pop();
56         while(te>0){
57             te=te/10;
58             if(mp[te]==true){
59                 flag=0;return;
60             }
61         }
62         //q.push(nt);
63     }
64 
65 }
66 
67 void solve()
68 {
69 
70 }
71 
72 void out()
73 {
74     if(flag==0){
75         printf("NO\n");
76     }
77     else{
78         printf("YES\n");
79     }
80 }
81 
82 int main()
83 {
84     //freopen("data.in","r",stdin);
85     //freopen("data.out","w",stdout);
86     scanf("%d",&T);
87     //for(int ccnt=1;ccnt<=T;ccnt++)
88     while(T--)
89     //scanf("%d%d",&n,&m);
90     //while(scanf("%d",&n)!=EOF)
91     {
92         ini();
93         solve();
94         out();
95     }
96     return 0;
97 }