#include <bits/stdc++.h>
using namespace std;
template <class T>
int getbit(T s, int i) {
  return (s >> i) & 1;
}
template <class T>
T onbit(T s, int i) {
  return s | (T(1) << i);
}
template <class T>
T offbit(T s, int i) {
  return s & (~(T(1) << i));
}
template <class T>
int cntbit(T s) {
  return __builtin_popcount(s);
}
template <class T>
inline T gcd(T a, T b) {
  T r;
  while (b != 0) {
    r = a % b;
    a = b;
    b = r;
  }
  return a;
}
long long l, k, n, r, m;
string s;
int main() {
  srand(time(0));
  cin >> n >> k;
  l = 1, r = n;
  while (1) {
    if (r - l + 1 <= 50) {
      long long tmp = (r - l + 1);
      long long t = rand() % tmp;
      cout << l + t << " " << l + t << "\n";
      fflush(stdout);
      cin >> s;
      if (s == "Yes")
        return 0;
      else {
        l = max(1LL, l - k);
        r = min(r + k, n);
      }
    } else {
      m = (l + r) >> 1;
      cout << l << " " << m << "\n";
      fflush(stdout);
      cin >> s;
      if (s == "Yes") {
        l = max(1LL, l - k);
        r = min(m + k, n);
      } else {
        l = max(1LL, m - k);
        r = min(r + k, n);
      }
    }
  }
  return 0;
}
