#include <bits/stdc++.h>
using namespace std;
const int N = 1002;
long long n, k;
string a;
long long myRand(long long n) {
  static long long first = 1;
  static long long second = 1;
  first = (first * 23 + 129) % 1000000007;
  second = (second * 31 + 37) % 1000000007;
  return ((first << 32) | second) % n;
}
void solve(long long &l, long long &r) {
  while (l < r and r - l + 1 > 5 * k) {
    long long mid = (l + r) / 2;
    cout << l << " " << mid << endl;
    cin >> a;
    if (a == "Yes") {
      if (l == mid) exit(0);
      l = max(1ll, l - k);
      r = min(n, mid + k);
    } else {
      l = max(1ll, mid + 1 - k);
      r = min(n, r + k);
    }
  }
}
int main() {
  cin >> n >> k;
  long long l = 1, r = n;
  while (true) {
    solve(l, r);
    long long random = myRand(r - l + 1);
    cout << l + random << " " << l + random << endl;
    cin >> a;
    if (a == "Yes") return 0;
    l = max(1ll, l - k);
    r = min(n, r + k);
  }
}
