#include <bits/stdc++.h>
using namespace std;
long long n, k, flag;
string s;
bool OK(long long l, long long r) {
  printf("%lld %lld\n", l, r);
  cin >> s;
  if (s[0] == 'N')
    return false;
  else if (s[0] == 'Y') {
    if (l == r) flag = 1;
    return true;
  }
}
int main() {
  srand(time(NULL));
  cin >> n >> k;
  long long l, r, mid;
  l = 1, r = n;
  while (1) {
    mid = (l + r) / 2;
    if (OK(l, mid)) {
      r = mid;
      if (flag) break;
    } else {
      l = mid + 1;
    }
    l = max((long long)1, l - k);
    r = min(n, r + k);
    mid = rand() % (r - l + 1) + l;
    OK(mid, mid);
    if (flag) break;
    l = max((long long)1, l - k);
    r = min(n, r + k);
  }
  return 0;
}
