#include <bits/stdc++.h>
using namespace std;
const char* a1 = "What are you doing while sending \"";
const char* a2 = "\"? Are you busy? Will you send \"";
const char* a3 = "\"?";
const char* f0 =
    "What are you doing at the end of the world? Are you busy? Will you save "
    "us?";
int la1 = strlen(a1);
int la2 = strlen(a2);
int la3 = strlen(a3);
int lf0 = strlen(f0);
long long memo[111111];
long long sz(long long n) {
  if (n == 0) return lf0;
  if (memo[n]) return memo[n];
  long long ret = la1 + sz(n - 1) + la2 + sz(n - 1) + la3;
  return memo[n] = ret;
}
char query(long long n, long long k) {
  if (n == 0) {
    if (k <= lf0)
      return f0[k - 1];
    else
      return '.';
  }
  if (n <= 53 && sz(n) < k) return '.';
  if (k <= n * la1) {
    return a1[(k - 1) % la1];
  } else {
    k -= la1;
    char p = query(n - 1, k);
    if (p != '.')
      return p;
    else {
      k -= sz(n - 1);
      if (k <= la2)
        return a2[k - 1];
      else {
        k -= la2;
        char p2 = query(n - 1, k);
        if (p2 != '.')
          return p2;
        else {
          k -= sz(n - 1);
          if (k <= la3)
            return a3[k - 1];
          else
            return '.';
        }
      }
    }
  }
}
int main() {
  int q;
  cin >> q;
  while (q--) {
    long long n, k;
    cin >> n >> k;
    putchar(query(n, k));
  }
  puts("");
  return 0;
}
