#include<bits/stdc++.h>
#include<windows.h>
using namespace std;
int main(){
	unsigned long long l,r,n,s,max,min;
	system("cls");
	srand(time(0));
	cout<<"输入最大值 (>=2,不能是字符) :";
	cin>>max;
	if(max<2){
		cout<<"输入的值应>=2!";
		Sleep(1000);
		main();
		return 0;
	}
	if(max>=1000000000){
		cout<<"太大了!";
		max=100;
		Sleep(1000);
		main();
		return 0;
	}
	l=0;r=max;
	n=(unsigned)rand()%max;
	if(!n)n=1;
	while(1){
		cout<<l<<"~"<<r<<endl;
		cin>>s;
		if(s<l)continue;
		else if(s>r)continue;
		else if(s==n)break;
		else if(s>l&&s<n)l=s;
		else if(s<r&&s>n)r=s;
	}
	cout<<"You win!";
	return 0;
}