#include<bits/stdc++.h>
using namespace std;

int main(){
  int t,x0,y0,xt,yt;
  cin>>t>>x0>>y0>>xt>>yt;
  auto dist=[&](int x1,int y1,int x2,int y2){return abs(x1-x2)+abs(y1-y2);};
  auto query=[&](int t){
    cout<<"? "<<t<<endl;
    int x,y;
    cin>>x>>y;
    return dist(x,y,x0,y0)-dist(x,y,xt,yt);
  };
  auto answer=[&](int t){
    cout<<"! "<<t<<endl;
    exit(0);
  };
  int l=0,r=t;
  if (query(0)==0) answer(0);
  if (query(t)==0) answer(t);
  while (r-l>1){
    int mid=(l+r)/2;
    int q=query(mid);
    if (q<=0) l=mid;
    else r=mid;
  }
  answer(l);
}