#nullable enable

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

var t = I<int>();
var x0 = I<int>();
var y0 = I<int>();
var xt = I<int>();
var yt = I<int>();

int D(int x0, int y0, int x1, int y1) => Math.Abs(x0 - x1) + Math.Abs(y0 - y1);

var pass = 0;
var fail = t;
while (Math.Abs(pass - fail) >= 2)
{
    var mid = (pass + fail) >> 1;
    Console.WriteLine("? " + mid);
    var xm = I<int>();
    var ym = I<int>();
    var f = D(x0, y0, xm, ym) <= D(xt, yt, xm, ym);
    if (f) pass = mid;
    else fail = mid;
}
Console.WriteLine("! " + pass);