#include <bits/stdc++.h>
using namespace std;
 
void testCase() {
 int n;cin>>n;
 bool dd[10]={false};
 for(int i=0;i<n;i++){
 	long long x;cin>>x;
 	while(x){
 		dd[x%10]=true;
 		x/=10;
	 }
 }
 for(int i=0;i<10;i++){
 	if(dd[i]) cout<<i<<" ";
 }
}
 
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);
 
    int T = 1; cin >> T;
    while (T--) {
        testCase();
        cout << "\n";
    }
    return 0;
}
 

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