// dfmt off
T lread(T=long)(){return readln.chomp.to!T;}T[] lreads(T=long)(long n){return iota(n).map!((_)=>lread!T).array;}
T[] aryread(T=long)(){return readln.split.to!(T[]);}void arywrite(T)(T a){a.map!text.join(' ').writeln;}
void scan(L...)(ref L A){auto l=readln.split;foreach(i,T;L){A[i]=l[i].to!T;}}alias sread=()=>readln.chomp();
void dprint(L...)(lazy L A){debug{auto l=new string[](L.length);static foreach(i,a;A)l[i]=a.text;arywrite(l);}}
static immutable MOD=10^^9+7;alias PQueue(T,alias l="b<a")=BinaryHeap!(Array!T,l);import std;
// dfmt on

void main()
{
    long N = lread();
    writeln(0);
    stdout.flush();
    long ok = 0;
    long ng = N;
    auto S = sread();
    if (S == "Vacant")
        return;
    while (true)
    {
        long m = (ok + ng) / 2;
        writeln(m);
        stdout.flush();
        auto s = sread();
        if (s == "Vacant")
            return;
        if ((S != s) == (m & 1))
        {
            ok = m;
        }
        else
        {
            ng = m;
        }
    }
}
