#include <bits/stdc++.h>
using namespace std;
#define TR(i,v)         for(__typeof((v).begin())i=(v).begin();i!=(v).end();++i)
#define DEBUG(x)        cout << #x << " = "; cout << x << endl;
#define SIZE(p)         (int)(p).size()
#define MP(a, b)        make_pair((a), (b))
#define ALL(p)          (p).begin(), (p).end()
#define rep(i, n)       for(int (i)=0; (i)<(int)(n); ++(i))
#define REP(i, a, n)    for(int (i)=(a); (i)<(int)(n); ++(i))
#define FOR(i, a, b)    for(int (i)=(int)(a); (i)<=(int)(b); ++(i))
#define FORD(i, b, a)   for(int (i)=(int)(b); (i)>=(int)(a); --(i))
#define CLR(x, y)       memset((x), (y), sizeof((x)))
typedef long long LL;
typedef pair<int, int> pii;

int main(int argc, char const *argv[]) {    
    ios::sync_with_stdio(false);        cin.tie(0);
    int P,V;    cin>>P>>V;    
    static int minp[100005],maxp[100005];
    FOR(i,0,V)  minp[i]=0,maxp[i]=P;
    rep(k,100) {
        LL cnt=0;
        FOR(i,0,V) if(~minp[i]) 
            cnt+=maxp[i]-minp[i]+1;                
        if(cnt==1) {
            int pos,speed;
            FOR(i,0,V) if(~minp[i]) pos=minp[i],speed=i;
            cout<<"answer "<<pos+speed*k<<endl;            
            return 0;
        }
        int l=0,r=(int)1e9;        
        while(l<r) {
            int mid=l+((r-l)>>1);
            LL c=0;
            FOR(i,0,V) if(~minp[i]) {
                LL t=mid-(LL)k*i;
                LL r=min((LL)maxp[i],t);
                if(r>=minp[i])
                    c+=r-minp[i]+1;
            }            
            if(c+c>=cnt)    r=mid;
            else            l=mid+1;
        }
        cout<<"check "<<0<<" "<<l<<endl;
        string s;
        cin>>s;        
        if(s[0]=='Y') {
            FOR(i,0,V) if(~minp[i]) {
                int t=l-(LL)k*i;
                if(t>=minp[i])  maxp[i]=min(maxp[i],t);
                else            minp[i]=maxp[i]=-1;
            }
        }else {
            FOR(i,0,V) if(~minp[i]) {
                int t=l-(LL)k*i+1;
                if(t<=maxp[i])  minp[i]=max(minp[i],t);
                else            minp[i]=maxp[i]=-1;
            }
        }        
    }
    assert(0);
    return 0;
}