#pragma GCC optimize("Ofast")

#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll = long long;
#define rep(i, s, t) for (ll i = s; i < (ll)(t); i++)
#define all(x) begin(x), end(x)

template <class T> bool chmin(T& x, T y) {
	return x > y ? (x = y, true) : false;
}
template <class T> bool chmax(T& x, T y) {
	return x < y ? (x = y, true) : false;
}

struct io_setup {
	io_setup() {
		ios::sync_with_stdio(false);
		cin.tie(nullptr);
		cout << fixed << setprecision(15);
	}
} io_setup;

void solve() {
	int k;
	string s;
	cin >> k >> s;
	auto shift_S = [&]() {
		s.insert(s.begin(), s[0]);
		s.pop_back();
	};
	if (k > 64) {
		cout << string(s.size(), s[0]) << '\n';
	} else {
		rep(i, 0, k) shift_S();
		cout << s << '\n';
	}
}

int main() {
	int t = 1;
	cin >> t;
	while (t--) solve();
}