#include <bits/stdc++.h>
using namespace std;
long long n;
int k;
void read() { cin >> n >> k; }
bool isYes() {
  string s;
  cin >> s;
  return s == "Yes";
}
void work() {
  long long L = 1;
  long long R = n;
  while (1) {
    while ((R - L) / 2 > k * 2) {
      long long mid = (L + R) / 2;
      cout << L << ' ' << mid << endl;
      cout.flush();
      if (isYes()) {
        R = mid + k;
        L = L - k;
      } else {
        R = R + k;
        L = mid - k + 1;
      }
      L = max(L, 1LL);
      R = min(R, n);
    }
    vector<long long> pos;
    for (long long i = L; i <= R; ++i) pos.push_back(i);
    random_shuffle(pos.begin(), pos.end());
    for (int i = 0; i < pos.size(); ++i) {
      cout << pos[i] << ' ' << pos[i] << endl;
      cout.flush();
      if (isYes()) {
        return;
      }
    }
    long long nTried = R - L + 1;
    L -= nTried * k;
    R += nTried * k;
    L = max(L, 1LL);
    R = min(R, n);
  }
}
int main() {
  read();
  work();
  return 0;
}
