// Online C++ compiler to run C++ program online
#include <iostream>
#include <vector>
#include <set>
using namespace std;
int main() {
/*
vector<int> nums = {
1, 2, 3, 4, 5, 6, 7, 8, 9,
11, 22, 33, 44, 55, 66, 77, 88, 99,
101, 111, 121, 131, 141, 151, 161, 171, 181, 191,
202, 212, 222, 232, 242, 252, 262, 272, 282, 292,
303, 313, 323, 333, 343, 353, 363, 373, 383, 393,
404, 414, 424, 434, 444, 454, 464, 474, 484, 494,
505, 515, 525, 535, 545, 555, 565, 575, 585, 595,
606, 616, 626, 636, 646, 656, 666, 676, 686, 696,
707, 717, 727, 737, 747, 757, 767, 777, 787, 797,
808, 818, 828, 838, 848, 858, 868, 878, 888, 898,
909, 919, 929, 939, 949, 959, 969, 979, 989, 999
};
vector<int> correctNums = {};
for (int i = 0; i < nums.size(); i++)
{
int k = 2;
bool addNum = true;
while (k * k < nums[i])
{
if (nums[i] % k == 0)
{
addNum = false;
break;
}
k += 1;
}
if (addNum)
correctNums.push_back(nums[i]);
}
for (int i = 0; i < correctNums.size(); i++)
cout << correctNums[i] << " ";
*/
vector<int> correctNums = {
2, 3, 4, 5, 7, 9, 11, 101, 121, 131, 151, 181, 191, 313, 353, 373, 383, 727, 757, 787, 797, 919, 929
};
int t;
cin >> t;
for (int test = 0; test < t; test++)
{
int n;
cin >> n;
bool found = false;
for (int i = 0; i < n; i++)
{
int interesting;
cin >> interesting;
for (int idx = 0; idx < correctNums.size() && !found; idx++)
if (correctNums[idx] == interesting)
{
cout << interesting << endl;
found = true;
break;
}
}
}
return 0;
}