#include <bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b) { return (b ? gcd(b, a % b) : a); }
long long inf = 1e9 + 7;
long long mod = 1e9 + 9;
vector<vector<long long>> a, prc, pst;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long n, k;
  cin >> n >> k;
  srand(10124214);
  long long l = 1, r = n;
  while (1) {
    while (r - l > 4 * k + 1) {
      long long mid = (l + r) / 2;
      cout << l << " " << mid << endl;
      string s;
      cin >> s;
      if (s == "Bad") return 0;
      if (s == "Yes") {
        r = min(n, mid + k);
        l = max((long long)1, l - k);
      } else {
        l = max((long long)1, mid - k + 1);
        r = min(n, r + k);
      }
    }
    long long len = r - l + 1;
    long long pos = rand() % len + l;
    cout << pos << " " << pos << endl;
    string s;
    cin >> s;
    if (s == "Bad") return 0;
    if (s == "Yes")
      return 0;
    else {
      l = max((long long)1, l - k);
      r = min(n, r + k);
    }
  }
}
