#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
long long f[N];
int base = 0;
char s[] = {
    "What are you doing at the end of the world? Are you busy? Will you save "
    "us?"};
char s2[] = {
    "What are you doing while sending ? Are you busy? Will you send ?"};
char s3[] = {"What are you doing while sending \""};
char s4[] = {"\"? Are you busy? Will you send \""};
char ttt[] = {
    "What are you doing while sending \"What are you doing at the end of the "
    "world? Are you busy? Will you save us?\"? Are you busy? Will you send "
    "\"What are you doing at the end of the world? Are you busy? Will you save "
    "us?\"?"};
int main() {
  f[0] = strlen(s);
  base = strlen(s2);
  int len1 = strlen(s3);
  int len2 = strlen(s4);
  for (int i = 1; i < N; i++) {
    f[i] = base + 2 * f[i - 1] + 4;
    if (f[i] > 1e18) break;
  }
  f[53] = 2e18;
  int q;
  int n;
  long long k;
  cin >> q;
  string ans = "";
  while (q--) {
    cin >> n >> k;
    if (n == 0) {
      if (k > f[0])
        ans += ".";
      else
        ans += s[k - 1];
      continue;
    }
    int flag = 0;
    while (1) {
      if (n > 53 && k > len1) {
        n--;
        k -= len1;
      } else if (n == 0) {
        if (k > f[0])
          ans += ".";
        else
          ans += s[k - 1];
        flag = 1;
        break;
      } else if (k <= len1) {
        ans += s3[k - 1];
        flag = 1;
        break;
      } else {
        break;
      }
    }
    if (flag) continue;
    while (1) {
      if (n == 0) {
        if (k > f[0])
          ans += ".";
        else
          ans += s[k - 1];
        break;
      }
      if (k > f[n]) {
        ans += ".";
        flag = 1;
        break;
      } else {
        if (k <= len1) {
          ans += s3[k - 1];
          flag = 1;
          break;
        } else if (k > len1 + len2 + f[n - 1]) {
          if (k <= len1 + len2 + 2 * f[n - 1]) {
            k -= len1 + len2 + f[n - 1];
            n--;
          } else {
            long long t = k - (len1 + len2 + 2 * f[n - 1]);
            ans += ((t == 1) ? "\"" : "?");
            flag = 1;
            break;
          }
        } else if (k <= len1 + f[n - 1]) {
          k -= len1;
          n--;
        } else {
          ans += s4[k - len1 - f[n - 1] - 1];
          flag = 1;
          break;
        }
      }
    }
    if (flag) continue;
  }
  cout << ans << endl;
  return 0;
}
