TLE 0分求调

#include<bits/stdc++.h>
const int N=1e9; 
int n;
int l=1,r=N;
int main() 
{
    std::cin>>n;
 	while(l<=r)
 	{
 		int mid=(l+r)/2;
 		int k,answer;
 		std::cout<<mid<<std::endl;
 		std::cin>>answer;
 		if(answer==0) return 0;
 		else if(answer==1) r=mid-1;
 		else if(answer==-1) l=mid+1;
	}
    return 0;
}