#include <bits/stdc++.h>
using namespace std;
template <typename T>
void printvec(vector<T>& vec) {
  for (int i = 0; i < vec.size(); i++) {
    cout << vec[i] << " ";
  }
  cout << endl;
}
long long n, k;
int turns = 0;
bool interact(long long a, long long b) {
  turns++;
  if (turns > 4500) {
    abort();
  }
  cout << a << " " << b << endl;
  fflush(stdout);
  string temp;
  cin >> temp;
  if (temp == "Yes") {
    if (a == b) {
      exit(0);
    }
    return true;
  } else if (temp == "No")
    return false;
  else
    abort();
}
int main() {
  std::ios::sync_with_stdio(false);
  srand(time(NULL));
  int ttt = 1;
  while (ttt--) {
    cin >> n >> k;
    long long l = 1, r = n, mid;
    while (1) {
      mid = (l + r) / 2;
      bool res = interact(l, mid);
      if (res) {
        l = max((long long)1, l - k);
        r = min(n, mid + k);
      } else {
        l = max((long long)1, mid + 1 - k);
        r = min(n, r + k);
      }
      long long sz = r - l + 1;
      if (sz < 5 * k) {
        long long guess = rand() % sz;
        interact(l + guess, l + guess);
        l = max((long long)1, l - k);
        r = min(n, r + k);
      }
    }
  }
  return 0;
}
