#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
const int N = 2e5 + 5;
long long n, k;
string ask(long long l, long long r) {
  cout << l << " " << r << endl;
  string s;
  cin >> s;
  assert(s != "Bad");
  if (l == r && s == "Yes") exit(0);
  return s;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  srand(time(0));
  cin >> n >> k;
  long long low = 1, high = n, mid;
  while (1) {
    if (high - low + 1 <= 50) {
      int x = rand() % (high - low + 1);
      string s = ask(x + low, x + low);
    } else {
      mid = low + high >> 1;
      string s = ask(low, mid);
      if (s == "Yes")
        high = mid;
      else
        low = mid + 1;
    }
    low = max(1ll, low - k);
    high = min(n, high + k);
  }
  return 0;
}
