#include <bits/stdc++.h>
using namespace std;
char s[10];
long long n, k;
signed main() {
  srand((unsigned long long)time(NULL));
  scanf("%I64d %I64d", &n, &k);
  long long l = 1, r = n;
  while (1) {
    if (r - l + 1 <= (k << 2)) {
      long long pos = 1LL * rand() * rand() % (r - l + 1) + l;
      printf("%I64d %I64d\n", pos, pos);
      fflush(stdout);
      scanf("%s", s);
      if (s[0] == 'Y') {
        return 0;
      } else if (s[0] == 'N') {
        l = max(l - k, 1LL);
        r = min(r + k, n);
      } else {
        return 0;
      }
    } else {
      long long mid = (l + r) >> 1;
      printf("%I64d %I64d\n", l, mid);
      fflush(stdout);
      scanf("%s", s);
      if (s[0] == 'Y' && l == mid) return 0;
      if (s[0] == 'Y') {
        l = max(l - k, 1LL);
        r = min(mid + k, n);
      } else if (s[0] == 'N') {
        l = max(mid + 1 - k, 1LL);
        r = min(r + k, n);
      } else {
        return 0;
      }
    }
  }
  return 0;
}
