#include <bits/stdc++.h>
using namespace std;
mt19937 gen(chrono::system_clock::now().time_since_epoch().count());
long long int n, m, a[1000005];
int main() {
  long long int k;
  scanf("%lld%lld", &n, &k);
  long long int lo = 1;
  long long int hi = n;
  while (lo <= hi) {
    if (hi - lo + 1 <= 4 * k + 1) {
      long long int len = hi - lo + 1;
      long long int ok = lo + gen() % (len);
      printf("%lld %lld\n", ok, ok);
      fflush(stdout);
      char ch[6];
      scanf("%s", ch);
      if (ch[0] == 'Y')
        return 0;
      else {
        lo = max(lo - k, 1LL);
        hi = min(hi + k, n);
      }
      continue;
    }
    long long int mid = (lo + hi) / 2;
    printf("%lld %lld\n", lo, mid);
    fflush(stdout);
    char ch[6];
    scanf("%s", ch);
    if (ch[0] == 'Y') {
      lo = max(lo - k, 1LL);
      hi = min(mid + k, n);
    } else {
      lo = max(1LL, mid - k + 1);
      hi = min(hi + k, n);
    }
  }
  return 0;
}
