#include <bits/stdc++.h>
using namespace std;
char a[10];
int main() {
  long long l, r, n, k, x, y;
  cin >> n >> k;
  l = 1;
  r = n;
  srand(0);
  while (1) {
    if (r - l <= k * 8) {
      x = y = (long long)(rand() % (r - l + 1)) + l;
      printf("%lld %lld\n", x, y);
      fflush(stdout);
      scanf("%s", a);
      if (strcmp(a, "Bad") == 0 || strcmp(a, "Yes") == 0) return 0;
      l = max((long long)1, l - k);
      r = min(n, r + k);
    } else {
      x = l;
      y = (l + r) / 2;
      printf("%lld %lld\n", x, y);
      fflush(stdout);
      scanf("%s", a);
      if (strcmp(a, "Bad") == 0) return 0;
      if (strcmp(a, "Yes") == 0) {
        if (x == y) return 0;
        r = y;
      } else
        l = y + 1;
      l = max((long long)1, l - k);
      r = min(n, r + k);
    }
  }
  return 0;
}
