#include<bits/stdc++.h>
using namespace std;
#define int long long
#define REP(i,m,n) for(int i=(m);i<(n);i++)
#define rep(i,n) REP(i,0,n)
#define pb push_back
#define all(a) a.begin(),a.end()
#define rall(c) (c).rbegin(),(c).rend()
#define mp make_pair
#define endl '\n'
#define vec vector<ll>
#define mat vector<vector<ll> >
#define fi first
#define se second
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll,ll> pll;
typedef long double ld;
typedef complex<double> comp;
const ll inf=1e9+7;
const ll mod=998244353;
const int MAX=1000010;



signed main(){
    ll l=1,r=1000;
    ll ans=1;
    while(r-l>1){
        ll mid=(r+l)/2;
        string s,t;
        cout<<'?'<<mid<<endl;
        cin>>s;
        cout<<'?'<<mid+1<<endl;
        cin>>t;
        if(t=="safe"){
            ans=max(ans,mid+1);
            l=mid+1;
        }else if(s=="safe"){
            ans=max(ans,mid);
            l=mid;
        }else{
            r=mid;
        }
    }
    cout<<'!'<<ans<<endl;
}