#nullable enable

#region
var _input = Array.Empty<string>();
var _iter = 0;
string String()
{
    while (_iter >= _input.Length) (_input, _iter) = (Console.ReadLine()!.Split(' '), 0);
    return _input[_iter++];
}
T I<T>() where T : IParsable<T> => T.Parse(String(), null);
#endregion

var t = I<int>();
var ans = new string[t];
for (var i = 0; i < t; i++)
{
    var k = I<int>();
    var s = String();
    k = Math.Min(k, s.Length + 1);
    for (var j = 0; j < k; j++) s = s[0] + s[..^1];
    ans[i] = s;
}
Console.WriteLine(string.Join(Environment.NewLine, ans));