#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, k;
  cin >> n >> k;
  long long l = 1, r = n;
  srand(time(0));
  while (true) {
    if (r - l > 120) {
      long long m = (l + r) / 2;
      cout << l << ' ' << m << endl;
      string s;
      cin >> s;
      if (s[0] == 'N')
        l = m + 1;
      else
        r = m;
      l -= k;
      r += k;
    } else {
      long long del = r - l + 1;
      long long x = rand() % del + l;
      cout << x << ' ' << x << endl;
      string s;
      cin >> s;
      if (s[0] == 'Y') {
        return 0;
      }
      l -= k;
      r += k;
    }
    if (l < 1) l = 1;
    if (r > n) r = n;
  }
  return 0;
}
