#include <bits/stdc++.h>
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wmissing-noreturn"
using namespace std;
bool scan(long long l, long long r) {
  cout << l << " " << r << endl;
  cout.flush();
  string s;
  cin >> s;
  if (l == r && s == "Yes") exit(0);
  if (s == "Bad") exit(0);
  return s == "Yes";
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  long long n, k;
  cin >> n >> k;
  long long a = 1, b = n;
  mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
  while (true) {
    if (b - a <= 50) {
      auto guess = uniform_int_distribution<long long>(a, b)(rng);
      scan(guess, guess);
      a = max(1ll, a - 10);
      b = min(n, b + 10);
    } else {
      auto mid = a + (b - a) / 2;
      if (scan(a, mid)) {
        a = max(1ll, a - 10);
        b = min(n, mid + 10);
      } else {
        a = max(1ll, mid + 1 - 10);
        b = min(n, b + 10);
      }
    }
  }
  return 0;
}
#pragma clang diagnostic pop
