#include <bits/stdc++.h>
using namespace std;
long long ml = 1e9 + 7;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  vector<long long> v;
  for (long long i = 1; i <= 10000; i++) v.push_back(1000000LL - 1LL + i);
  random_shuffle(v.begin(), v.end());
  long long n, k;
  cin >> n >> k;
  k = 10;
  long long lo = 1, hi = n, cnt = 0;
  while (true) {
    long long id = -1;
    ml--;
    long long t = clock();
    long long dff = hi - lo + 1;
    long long rn = (v[++id] * t) % dff;
    cout << min(lo + rn, n) << " " << min(lo + rn, n) << endl;
    fflush(stdout);
    cnt++;
    string s;
    cin >> s;
    if (s == "Bad") exit(0);
    if (s == "Yes")
      exit(0);
    else {
      lo = max(1LL, lo - k);
      hi = min(n, hi + k);
    }
    long long md = (lo + hi) / 2;
    cout << lo << " " << md << endl;
    fflush(stdout);
    cnt++;
    cin >> s;
    if (s == "Bad") exit(0);
    if (s == "Yes") {
      lo = max(1LL, lo - k);
      hi = min(n, md + k);
    } else {
      lo = max(1LL, md - k);
      hi = min(n, hi + k);
    }
  }
  return 0;
}
