#include <bits/stdc++.h>
using namespace std;
const int inf = 1e9 + 9;
const long long int MOD = 1e9 + 696969;
const long long INF = 1e18 + 3;
long long int n, k;
long long int X, Y;
int que;
bool ask(long long int x, long long int y) {
  ++que;
  assert(que <= 4500);
  cout << x << ' ' << y << endl;
  string ans;
  cin >> ans;
  if (ans == "Yes" && x == y) exit(0);
  return (ans == "Yes");
}
int main() {
  srand(time(0));
  ios_base::sync_with_stdio(false);
  cin >> n >> k;
  X = 1;
  Y = n;
  while (que <= 4500) {
    if (Y - X > 40) {
      long long int mid = (X + Y) / 2;
      if (ask(X, mid))
        Y = mid;
      else
        X = mid + 1;
      X = max(1LL, X - k);
      Y = min(n, Y + k);
    } else {
      long long int diff = rand() % (Y - X + 1);
      if (ask(X + diff, X + diff)) exit(0);
      X = max(1LL, X - k);
      Y = min(n, Y + k);
    }
  }
}
