func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long oo = 3e18, M = 54;   long long q, n, k;   string F =        What are you doing at the end of the world? Are you busy? Will you save          us? ;   string X =  What are you doing while sending   ;   string Y =   ? Are you busy? Will you send   ;   string Z =   ? ;   long long length(int n) {     if (n >= M) {       return oo;     }     long long tot = X.size() + Y.size() + Z.size();     long long len = ((1LL << n) - 1) * tot + (1LL << n) * F.size();     return len;   }   char solve(long long i, long long k) {     if (i == 0) {       return k > F.size() ?  .  : F[k - 1];     }     long long len = length(i - 1);     if (X.size() + len + Y.size() + len + Z.size() < k) {       return  . ;     } else if (X.size() + len + Y.size() + len < k) {       k -= X.size() + len + Y.size() + len;       return Z[k - 1];     } else if (X.size() + len + Y.size() < k) {       k -= X.size() + len + Y.size();       return solve(i - 1, k);     } else if (X.size() + len < k) {       k -= X.size() + len;       return Y[k - 1];     } else if (X.size() < k) {       k -= X.size();       return solve(i - 1, k);     } else {       return X[k - 1];     }   }   int main() {     cin >> q;     while (q--) {       cin >> n >> k;       cout << solve(n, k);     }     return 0;   }   