#include <bits/stdc++.h>
inline int64_t max(int64_t a, int64_t b) { return a > b ? a : b; }
inline int64_t min(int64_t a, int64_t b) { return a < b ? a : b; }
bool ask(int64_t l, int64_t r) {
  std::cout << l << ' ' << r << std::endl;
  std::string s;
  std::cin >> s;
  return s == "Yes";
}
int main() {
  std::mt19937 g(time(0));
  int64_t n, k, L, R, now, mid;
  std::cin >> n >> k;
  for (L = 1, R = n;;) {
    while (R - L > 42)
      if (ask(L, mid = L + R >> 1))
        L = max(1ll, L - k), R = min(n, mid + k);
      else
        L = max(1ll, mid + 1 - k), R = min(n, R + k);
    now = L + llabs(g()) % (R - L + 1);
    if (ask(now, now))
      return 0;
    else
      L = max(1ll, L - k), R = min(n, R + k);
  }
  return 0;
}
