#include <bits/stdc++.h>
using namespace std;
long long n, k;
long long nl, nr;
void ask() {
  long long tmp = nl + (nr - nl) / 2;
  printf("%I64d %I64d", nl, tmp);
  cout << endl;
  string s;
  cin >> s;
  if (s == "Yes") {
    if (nl == tmp) exit(0);
    nl = max(1LL, nl - k);
    nr = min(n, tmp + k);
  } else {
    nl = max(1LL, tmp + 1 - k);
    nr = min(n, nr + k);
  }
}
void ask2() {
  long long tmp;
  if (nr != nl)
    tmp = nl + (rand() * 107) % (nr - nl + 1);
  else
    tmp = nl;
  printf("%I64d %I64d", tmp, tmp);
  cout << endl;
  string s;
  cin >> s;
  if (s == "Yes") {
    exit(0);
  } else {
    nl = max(1LL, nl - k);
    nr = min(n, nr + k);
  }
}
int main() {
  srand(time(0));
  cin >> n >> k;
  nl = 1;
  nr = n;
  for (;;) {
    if (nr - nl >= 4 * k)
      ask();
    else
      ask2();
  }
}
