#include <bits/stdc++.h>
using namespace std;
ofstream fo("test.out");
ifstream fi("test.inp");
const long long MOD = 1e9 + 7;
const long long base = 269;
const int oo = 1 << 30;
const int N = 1e5 + 5;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
long long n, m, q, k, pos, rs;
long long x, y, ca, cb;
long long a[N];
bool check(long long l, long long r) {
  printf("%lld %lld\n", l, r);
  fflush(stdout);
  string s;
  cin >> s;
  if (s == "Yes" && l == r) exit(0);
  return s == "Yes";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  cin >> n >> k;
  long long l = 1, r = n, mid = (l + r) >> 1;
  while (1) {
    long long len = r - l + 1;
    if (len >= 4 * k + 2) {
      mid = (l + r) >> 1;
      if (check(l, mid))
        r = mid;
      else
        l = mid + 1;
    } else {
      long long x = rng() % (r - l + 1) + l;
      check(x, x);
    }
    l = max(1ll, l - k);
    r = min(n, r + k);
  }
}
