#include <bits/stdc++.h>
using namespace std;
long long n, k;
char s[10];
int main() {
  scanf("%lld%lld", &n, &k);
  srand(time(NULL));
  long long l = 1ll, r = n;
  while (true) {
    if (r - l + 1 > 41) {
      long long mid = (l + r) / 2;
      printf("%lld %lld\n", l, mid);
      fflush(stdout);
      scanf("%s", s);
      if (s[0] == 'Y')
        l = max(1ll, l - k), r = min(n, mid + k);
      else if (s[0] == 'N')
        l = max(1ll, mid + 1 - k), r = min(n, r + k);
      else
        break;
    } else {
      long long t = l + rand() % (r - l + 1);
      printf("%lld %lld\n", t, t);
      fflush(stdout);
      scanf("%s", s);
      if (s[0] == 'Y')
        break;
      else if (s[0] == 'N')
        l = max(1ll, l - k), r = min(n, r + k);
      else
        break;
    }
  }
  return 0;
}
