#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> VI;
#define REP(i, n) for(int(i)=0;(i)<(n);++(i))
#define in(T,V) T V;cin>>V;
const int MOD = int(1e9+7);
const int dv = 3;
int query(ll &L, ll &R){
    int d = (R-L)/dv;
    if(d == 0) d = 1;
    //fprintf(stderr, "L = %lld, R = %lld, d = %d\n", L, R, d);
    for(ll i = L+d; i <= L+d*dv; i += d){
        printf("? %lld\n", i);
    }
    int m[dv];
    REP(i,dv) cin >> m[i];
    REP(i,dv){
        if(m[i] == 1) L += d;
        if(m[i] == 0){ R = L + d*(i+1)-1; break; }
    }
    if(L == R) return L;
    return -1;
}

int main(){
    ll L = 1, R = 1e9;
    while(1){
        int r = query(L,R);
        if(r >= 0){
            printf("! %d\n", r);
            break;
        }
    }
}