#include <bits/stdc++.h>
using namespace std;
char inp[5];
void try_catch(long long int l, long long int r) {
  long long int mid = l + rand() % (r - l + 1);
  printf("%lld %lld\n", mid, mid);
  fflush(stdout);
  scanf("%s", inp);
  if (inp[0] == 'Y') exit(0);
}
int main() {
  srand(time(NULL));
  long long int n, k;
  cin >> n >> k;
  long long int l = 1, r = n;
  while (1) {
    while (r - l < 60) {
      try_catch(max(1LL, l - k), min(n, r + k));
      l = max(1LL, l - 2 * k);
      r = min(n, r + 2 * k);
    }
    long long int mid = (l + r) / 2;
    printf("%lld %lld\n", l, mid);
    fflush(stdout);
    scanf("%s", inp);
    if (inp[0] == 'Y') {
      if (l == mid) exit(0);
      r = min(n, mid + k);
      l = max(1LL, l - k);
    } else {
      l = max(1LL, mid - k);
      r = min(n, r + k);
    }
  }
  return 0;
}
