#include <bits/stdc++.h>
using namespace std;
char s[10];
int ask(long long l, long long r) {
  printf("%lld %lld\n", l, r);
  fflush(stdout);
  scanf("%s", s);
  return (s[0] == 'Y');
}
int main() {
  long long n, k;
  scanf("%lld%lld", &n, &k);
  long long l = 1, r = n;
  default_random_engine generator;
  while (1) {
    while (r - l >= 45) {
      long long mid = l + r >> 1;
      if (ask(l, mid))
        r = mid;
      else
        l = mid;
      l = max(1ll, l - k);
      r = min(n, r + k);
    }
    uniform_int_distribution<int> distribution(0, (int)(r - l));
    long long t = l + (long long)distribution(generator);
    if (ask(t, t))
      return 0;
    else {
      l = max(1ll, l - k);
      r = min(n, r + k);
    }
  }
}
