#include <bits/stdc++.h>
using namespace std;
char re[105];
bool query(long long l, long long r) {
  printf("%lld %lld\n", l, r);
  fflush(stdout);
  scanf("%s", re);
  return re[0] == 'Y';
}
long long N, K;
int main() {
  srand(time(NULL));
  scanf("%lld %lld", &N, &K);
  long long l = 1, r = N;
  while (l + 53 < r) {
    long long mid = l + r >> 1;
    if (query(l, mid)) {
      r = min(N, mid + K);
      l = max(1ll, l - K);
    } else {
      l = max(1ll, mid + 1 - K);
      r = min(N, r + K);
    }
  }
  while (1) {
    long long t = l + rand() % (r - l + 1);
    if (query(t, t)) return 0;
    l = max(1ll, l - K);
    r = min(N, r + K);
    while (l + 53 < r) {
      long long mid = l + r >> 1;
      if (query(l, mid)) {
        r = min(N, mid + K);
        l = max(1ll, l - K);
      } else {
        l = max(1ll, mid + 1 - K);
        r = min(N, r + K);
      }
    }
  }
}
