Codeforces Round #499 (Div. 2)D. Rocket

#include<bits/stdc++.h>
#include<set>
#include<cstdio>
#include<iomanip>
#include<iostream>
#include<string>
#include<cstring>
#include<algorithm>
#define pb push_back
#define ll long long
#define fi first
#define se second
#define PI 3.14159265
#define ls l,m,rt<<1
#define rs m+1,r,rt<<1|1
#define eps 1e-7
#define pii pair<int,int>
typedef unsigned long long ull;
const int mod=1e3+5;
const ll inf=0x3f3f3f3f3f3f3f;
const int maxn=1e5+5;
using namespace std;
int n,k,m;
int op[100];
int main()
{
    ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    cin>>m>>n;
    int x;
    for(int i=1;i<=n;i++)
    {
        cout<<1<<endl;
        cout.flush();
        cin>>x;
        if(x==0)exit(0);
        else if(x==1)op[i]=1;
        else op[i]=0;
    }
    int l=1,r=m;int cn=1;
    while(l<=r)
    {
        int mid=(l+r)>>1;
        cout<<mid<<endl;
        cout.flush();
        cin>>x;
        if(x==0)exit(0);
        if(op[cn])
        {
            if(x==1)l=mid+1;
            else r=mid-1;
        }
        else
        {
            if(x!=1)l=mid+1;
            else r=mid-1;
        }
        cn++;
        if(cn>n)cn-=n;
    }
    return 0;
}