#include <bits/stdc++.h>
using namespace std;
string w1 =
    "What are you doing at the end of the world? Are you busy? Will you save "
    "us?";
const int w1l = w1.length();
string w2a = "What are you doing while sending \"";
const int w2al = w2a.length();
string w2b = "\"? Are you busy? Will you send \"";
const int w2bl = w2b.length();
string w2c = "\"?";
const int w2cl = w2c.length();
long long k, n;
bool stop;
void test(long long kk, string s, int l) {
  if (stop) return;
  if (l >= k - kk) {
    printf("%c", s[k - kk - 1]);
    stop = true;
  }
}
long long rec(long long kk, int d) {
  if (stop) return 0;
  if (d == 0) {
    test(kk, w1, w1l);
    kk += w1l;
    return kk;
  } else {
    test(kk, w2a, w2al);
    kk += w2al;
  }
  long long kr = rec(kk, d - 1);
  long long kd = kr - kk;
  kk = kr;
  test(kk, w2b, w2bl);
  kk += w2bl;
  if (kk + kd + w2cl + 1 > k) {
    kk = rec(kk, d - 1);
    test(kk, w2c, w2cl);
  } else {
    kk += kd;
  }
  kk += w2cl;
  return kk;
}
int main() {
  int q;
  scanf("%d", &q) == 0;
  for (decltype(0) i = 0; i < q; i++) {
    scanf("%I64d", &n) == 0, scanf("%I64d", &k) == 0;
    stop = false;
    long long kk = rec(0, n);
    if (!stop) {
      if (k - kk == 0) {
        printf("%c", '?');
      } else {
        printf("%c", '.');
      }
    }
  }
  printf("%s\n", "");
}
