#include <cstdio> #include <cstring> #include <cmath> #include <algorithm> using namespace std; //namaega184 int main(){ int left=0,right=1000000000,mid=0; while(left<right){ mid=(left+right)/2; printf("? %d\n",mid); fflush(stdout); int res; scanf("%d",&res); if(res){ left=mid; } else{ right=mid-1; } } printf("! %d\n",mid); fflush(stdout); return 0; }