#include <bits/stdc++.h>
using namespace std;
mt19937 rnd(239);
bool ask(long long l, long long r) {
  cout << l + 1 << ' ' << r << endl;
  string s;
  cin >> s;
  if (s == "Yes") {
    if (l + 1 == r) {
      exit(0);
    }
    return 1;
  }
  if (s == "Bad") {
    exit(0);
  }
  return 0;
}
int solve() {
  long long n;
  cin >> n;
  int k;
  cin >> k;
  long long l = 0, r = n;
  while (true) {
    long long x = rnd() % (r - l) + l;
    ask(x, x + 1);
    l = max(l - k, 0LL);
    r = min(r + k, n);
    long long mid = (r + l) / 2LL;
    if (ask(l, mid)) {
      l = max(l - k, 0LL), r = min(mid + k, n);
    } else {
      l = max(mid - k, 0LL), r = min(r + k, n);
    }
  }
  return 1;
}
int32_t main() {
  ios::sync_with_stdio(0);
  int T = 100;
  for (int i = 1; i <= T; i++) {
    if (solve()) break;
  }
  return 0;
}
