//interactive
ll@(T,x,y,z,w),l=0,r=T,m;while(l<r-1){m=(l+r)/2,wt("?",m);ll@u,@v;(abs(u-x)+abs(v-y)-abs(u-z)-abs(v-w)>0?r:l)=m;}wt("!",x==z&y==w?T:l);