// tested by Hightail - https://github.com/dj3500/hightail
import std.stdio, std.string, std.conv, std.algorithm;
import std.range, std.array, std.math, std.typecons, std.container, core.bitop;
import std.datetime, std.bigint;

int N;

void main() {
    char ans;
    int k = -1;

    foreach (i ; 0 .. 10) {
        writefln("? %s", 10^^i);
        stdout.flush();
        scan(ans);

        if (ans == 'N') {
            k = i - 1;
            break;
        }
    }

    if (k == -1) {
        foreach (i ; 1 .. 10) {
            writefln("? %s", 10^^i - 1);
            stdout.flush();
            scan(ans);

            if (ans == 'Y') {
                writefln("! %s", 10^^(i - 1));
                stdout.flush();
                return;
            }
        }

        writefln("! %s", 10^^9);
        stdout.flush();
        return;
    }

    long btm = 10L^^k - 1, top = 10L^^(k + 1);

    while (top - btm > 1) {
        long mid = btm + (top - btm) / 2;
        writefln("? %s", mid * 10L);
        stdout.flush();
        scan(ans);

        if (ans == 'Y') top = mid;
        else btm = mid;
    }

    writefln("! %s", top);
    stdout.flush();
    return;
}

void scan(T...)(ref T args) {
    string[] line = readln.split;
    foreach (ref arg; args) {
        arg = line.front.to!(typeof(arg));
        line.popFront();
    }
    assert(line.empty);
}


void fillAll(R, T)(ref R arr, T value) {
    static if (is(typeof(arr[] = value))) {
        arr[] = value;
    }
    else {
        foreach (ref e; arr) {
            fillAll(e, value);
        }
    }
}