#include <bits/stdc++.h>
using namespace std;
constexpr int INF = 1e9 + 7;
constexpr long long INFL = 1e18;
long long n, k;
bool query(long long l, long long r) {
  cout << l << " " << r << endl;
  string ans;
  cin >> ans;
  if (l == r and ans == "Yes") exit(0);
  return ans == "Yes";
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  srand(time(0));
  cin >> n >> k;
  long long l = 1, r = n;
  while (true) {
    if (r - l <= 4 * k) {
      long long x = rand() % (r - l + 1) + l;
      query(x, x);
      l = max(1LL, l - k), r = min(n, r + k);
    } else {
      long long s = (l + r) / 2;
      if (query(l, s))
        l = max(1LL, l - k), r = min(n, s + k);
      else
        l = max(1LL, s - k + 1), r = min(n, r + k);
    }
  }
  return 0;
}
