import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }




void main() {
  const N = readInt;
  
  auto lpf = iota(N + 1).array;
  foreach (p; 2 .. N + 1) if (lpf[p] == p) {
    for (int n = 2 * p; n <= N; n += p) chmin(lpf[n], p);
  }
  int[] as;
  foreach (p; 2 .. N + 1) if (lpf[p] == p) {
    int n = p;
    for (; n * p <= N; n *= p) {}
    as ~= n;
  }
  as.sort;
  assert(as.length <= 0x600);
  
  int ans = 1;
  foreach (a; as) {
    writeln("? ", a);
    stdout.flush;
    const g = readInt;
    ans *= g;
  }
  writeln("! ", ans);
  stdout.flush;
}