#include <bits/stdc++.h>
using namespace std;
long long n, m, l, r, k;
string s;
long long check(long long l, long long r) {
  printf("%lld %lld\n", l, r);
  fflush(stdout);
  cin >> s;
  if (s[0] == 'Y') return 1;
  return 0;
}
int main() {
  srand(time(0));
  cin >> n >> k;
  l = 1;
  r = n;
  while (1) {
    while (r - l > 50) {
      long long mid = (l + r) / 2;
      if (check(l, mid))
        r = mid;
      else
        l = mid + 1;
      l = max(1ll, l - k), r = min(n, r + k);
    }
    long long q = rand() % (r - l + 1) + l;
    if (check(q, q)) return 0;
    l = max(1ll, l - k), r = min(n, r + k);
  }
}
