#include <bits/stdc++.h>
using namespace std;
mt19937_64 rnd(22);
long long n, k;
long long trainPos;
bool askQuery(long long l, long long r) {
  cout << l << " " << r << '\n';
  cout.flush();
  string res;
  cin >> res;
  return ((res == "Yes") ? true : false);
}
void adjust(long long &l, long long &r) {
  l = max(1LL, l - k);
  r = min(n, r + k);
}
void shrink(long long &l, long long &r) {
  long long mid = (l + r) / 2;
  if (askQuery(l, mid) == true)
    r = mid;
  else
    l = mid + 1;
  adjust(l, r);
}
void shrinkUntil(long long &l, long long &r, long long C) {
  while (r - l + 1 > C) {
    shrink(l, r);
  }
}
long long randInRange(long long l, long long r) {
  return l + rnd() % (r - l + 1);
}
int main() {
  cin >> n >> k;
  long long l = 1, r = n;
  while (true) {
    shrinkUntil(l, r, max(4 * k + 2, 5LL));
    long long pos = randInRange(l, r);
    if (askQuery(pos, pos) == true) {
      break;
    } else {
      adjust(l, r);
    }
  }
}
