#include <bits/stdc++.h>
using namespace std;
string s;
long long int n, k;
long long int L, R;
bool query(long long int l, long long int r) {
  l = max(1LL, l);
  r = min(n, r);
  cout << l << " " << r << endl;
  cin >> s;
  if (s == "Bad") exit(0);
  if (s == "Yes") {
    if (l == r) exit(0);
    return true;
  }
  return false;
}
int main() {
  ios_base::sync_with_stdio(0);
  srand(time(NULL));
  string s;
  cin >> n >> k;
  L = 1;
  R = n;
  while (true) {
    long long int len = (R - L + 1);
    if (len <= 5 * k + 4) {
      len = rand() % len;
      query(L + len, L + len);
      L = max(1LL, L - k);
      R = min(n, R + k);
    } else {
      long long int M = (L + R) / 2;
      if (query(L, M)) {
        L = L - k;
        R = M + k;
      } else {
        L = M - k;
        R = R + k;
      }
    }
    L = max(1LL, L);
    R = min(n, R);
  }
  exit(0);
}
