#include <bits/stdc++.h>
using namespace std;
char buf[10];
void guess(long long lhs, long long rhs) {
  printf("%lld %lld\n", lhs, rhs);
  fflush(stdout);
}
int main() {
  unsigned seed1 = std::chrono::system_clock::now().time_since_epoch().count();
  mt19937 g1;
  g1.seed(seed1);
  long long n, k;
  scanf("%lld%lld", &n, &k);
  long long lhs = 1;
  long long rhs = n;
  while (true) {
    if (rhs - lhs <= 4 * k) {
      int sz = rhs - lhs + 1;
      int inc = g1() % sz;
      if (inc < 0) inc += sz;
      guess(lhs + inc, lhs + inc);
      scanf("%s", buf);
      if (buf[0] == 'Y') return 0;
      assert(buf[0] == 'N');
    } else {
      long long mid = (lhs + rhs) / 2;
      guess(lhs, mid);
      scanf("%s", buf);
      if (buf[0] == 'Y')
        rhs = mid;
      else {
        assert(buf[0] == 'N');
        lhs = mid + 1;
      }
    }
    lhs = max(1LL, lhs - k);
    rhs = min(n, rhs + k);
  }
}
