/**
*/
#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
const int maxn=10000+10;
int N,M;
bool flag;
char state1[10],state2[10];

int main()
{
//#ifdef _WY
//freopen("0905.in","r",stdin);
//#endif // _WY

	//scanf("%d",&N);
	cin>>N;
	int lo=0,hi=N-1,mid;flag=true;
	while(lo<=hi){
        if(flag){
            mid=(lo+hi)/2;
            cout<<mid<<endl;//printf("%d\n",mid);
            cin>>state1;//scanf("%s",state1);
            if(state1[0]=='V'){break;}
        }
		if(lo!=mid){
			cout<<lo<<endl;//printf("%d\n",lo);
			cin>>state2;//scanf("%s",state2);
			if(state2[0]=='V'){break;}
			else{
				int len=mid-lo+1;
				if(state2[0]==state1[0]){
					hi=mid-1;lo=lo+1;flag=true;continue;
				}
			}
		}

		if(hi!=mid){
			cout<<hi<<endl;//printf("%d\n",hi);
			cin>>state2;//scanf("%s",state2);
			if(state2[0]=='V'){break;}
			else{
				int len=hi-mid+1;
				if(state2[0]==state1[0]){
					lo=mid+1;hi=hi-1;flag=true;continue;
				}
			}
		}
		lo=lo+1;hi=hi-1;
		flag=false;
	}
	return 0;
}
