cf1104d二分+数学

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

bool ask(int x,int y){
    printf("? %d %d\n",x,y);
    fflush(stdout);
    char buf[];
    scanf("%s",buf);
    return buf[]=='x';
}

int work(){
    if(ask(,))return ;
    int l=,r,ans,mid;
    while(ask(l*,l))l*=;
    r=l*+,r=min(r,);
    while(l<=r){
        mid=l+r>>;
        if(ask(mid,(mid+)/))//mid小于猜的数
            l=mid+;
        else ans=mid,r=mid-;
    }
    return ans;

}

int main(){
    char cmd[];
    while(){
        scanf("%s",cmd);
        if(strcmp(cmd,"start")==){
            printf("! %d\n",work());
            fflush(stdout);
        }
        else break;
    }
}