#include <bits/stdc++.h>
#define F first
#define S second
#define X real()
#define Y imag()
using namespace std;
typedef long long ll;
typedef long double ld;
int pp[2020];
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
pp[0]=1;
pp[1]=1;
for (int i=2;i<=1000;i++){
for (int j=2;j*i<=1000;j++){
pp[j*i]=1;
}
}
int tcs;
cin>>tcs;
for (int tc=0;tc<tcs;tc++){
int n;
cin>>n;
for (int i=0;i<n;i++){
int a;
cin>>a;
if (pp[a]==0){
string lol=to_string(a);
string asd=lol;
reverse(lol.begin(), lol.end());
if (lol==asd){
cout<<a<<'\n';
}
}
}
}
}