#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC target("arch=corei7-avx")
using ll = long long;
using namespace std;
namespace program {
mt19937 randint;
ll n, k;
bool ask(ll l, ll r) {
  cout << l << ' ' << r << endl;
  string res;
  cin >> res;
  bool ans = (res == "Yes");
  return ans;
}
void play(ll l, ll r) {
  if (r - l + 1 <= 100) {
    ll g = uniform_int_distribution<ll>(l, r)(randint);
    if (ask(g, g)) {
      exit(0);
    } else {
      play(max(l - k, 1LL), min(r + k, n));
    }
  } else {
    ll m = (l + r) / 2;
    if (ask(l, m)) {
      play(max(l - k, 1LL), min(m + k, n));
    } else {
      play(max(m + 1 - k, 1LL), min(r + k, n));
    }
  }
}
void run() {
  randint.seed(chrono::steady_clock::now().time_since_epoch().count() + 1);
  cin >> n >> k;
  play(1, n);
}
}  // namespace program
int main() {
  ios::sync_with_stdio(0);
  cin.tie();
  cout.tie();
  program::run();
  return 0;
}
