#include <bits/stdc++.h>
using namespace std;
bool checkbit(int x, int y) { return (x & (1 << y)); }
int setbit(int x, int y) { return (x ^ (1 << y)); }
const int dirs[4][2] = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
const int mod = 1e9 + 7;
const int p1 = 805306457;
const int p2 = 1610612741;
const int INF = 1e9;
const int N = 1e5 + 7;
long long n;
int k;
int qry(long long l, long long r) {
  cout << l << ' ' << r << '\n';
  cout.flush();
  string reply;
  cin >> reply;
  if (reply == "Yes" && l == r) exit(0);
  if (reply == "Yes")
    return 1;
  else
    return 2;
}
const long long FACT = 5e3;
int main() {
  mt19937 rnd(time(NULL));
  cin >> n >> k;
  long long ss = 1, se = n;
  while (1) {
    while (ss < se && se - ss + 1 > FACT) {
      if (qry(ss, ((ss + se) >> 1)) == 1) {
        ss = ss - k;
        if (ss < 1) ss = 1;
        se = ((ss + se) >> 1) + k;
        if (se > n) se = n;
      } else {
        ss = ((ss + se) >> 1) + 1 - k;
        if (ss < 1) ss = 1;
        se = se + k;
        if (se > n) se = n;
      }
    }
    long long t = rnd() % (se - ss + 1) + ss;
    qry(t, t);
    ss = ss - k;
    if (ss < 1) ss = 1;
    se = se + k;
    if (se > n) se = n;
  }
  return 0;
}
