#include <bits/stdc++.h>
using namespace std;
int main() {
  int i, k;
  srand(time(0));
  long long n, l, r, x;
  scanf("%lld", &n);
  scanf("%d", &k);
  l = 1;
  r = n;
  char str[30];
  for (i = 0; i < 4500; i++) {
    if (r - l < 50) {
      x = rand() % (r - l + 1) + l;
      printf("%lld %lld\n", x, x);
      fflush(stdout);
      scanf("%s", str);
      if (strcmp(str, "Yes") == 0) {
        break;
      } else if (strcmp(str, "Bad") == 0)
        break;
      l = max(1ll, l - k);
      r = min(n, r + k);
    } else {
      x = (l + r) / 2;
      printf("%lld %lld\n", l, x);
      fflush(stdout);
      scanf("%s", str);
      if (strcmp(str, "Bad") == 0)
        break;
      else if (strcmp(str, "Yes") == 0) {
        l = max(1ll, l - k);
        r = min(n, x + k);
      } else {
        x = min(n, x + 1);
        l = max(1ll, x - k);
        r = min(n, r + k);
      }
    }
  }
  return 0;
}
