description: You are given an integer n. Find any string s of length n consisting only of English lowercase letters such that each non-empty substring of s occurs in s an odd number of times. If there are multiple such strings, output any. It can be shown that such string always exists under the given constraints.
  
  A string a is a substring of a string b if a can be obtained from b by deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters from the end.
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 500) — the number of test cases.
  
  The first line of each test case contains a single integer n (1 ≤ n ≤ 10^5).
  
  It is guaranteed that the sum of n over all test cases doesn't exceed 3 ⋅ 10^5.
  
  Output
  
  For each test case, print a single line containing the string s. If there are multiple such strings, output any. It can be shown that such string always exists under the given constraints.
  
  Example
  
  Input
  
  
  4
  3
  5
  9
  19
  
  
  Output
  
  
  abc
  diane
  bbcaabbba
  youarethecutestuwuu
  
  Note
  
  In the first test case, each substring of "abc" occurs exactly once.
  
  In the third test case, each substring of "bbcaabbba" occurs an odd number of times. In particular, "b" occurs 5 times, "a" and "bb" occur 3 times each, and each of the remaining substrings occurs exactly once.
solution: import java.io.*;
  import java.util.StringTokenizer;
  
  public class Main {
      
      public static void main(String[] args) throws IOException {
          Scanner scn = new Scanner(System.in);
          OutputWriter out = new OutputWriter(System.out);
          // Always print a trailing "\n" and close the OutputWriter as shown at the end of your output
          
          // example:
          int t=scn.nextInt();
          for(int i1=0;i1<t;i1++){
              int n=scn.nextInt();
              if(n==1){
                  out.print("a\n");
              }
              else if(n%2==0){
                  for(int i=0;i<n/2;i++){
                      out.print("a");
                  }
                  out.print("b");
                  for(int i=0;i<n/2-1;i++){
                      out.print("a");
                  }
                  out.print("\n");
              }
              else{
                  for(int i=0;i<n/2;i++){
                      out.print("a");
                  }
                  out.print("b");
                  out.print("c");
                  for(int i=0;i<n/2-1;i++){
                      out.print("a");
                  }
                  out.print("\n");
              }
          }
          out.close();
      }
  
      // fast input
      static class Scanner {
          public BufferedReader reader;
          public StringTokenizer tokenizer;
  
          public Scanner(InputStream stream) {
              reader = new BufferedReader(new InputStreamReader(stream));
              tokenizer = null;
          }
  
          public String next() {
              while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                  try {
                      String line = reader.readLine();
                      if (line == null)
                          return null;
                      tokenizer = new StringTokenizer(line);
                  } catch (Exception e) {
                      throw(new RuntimeException());
                  }
              }
              return tokenizer.nextToken();
          }
  
          public int nextInt() { return Integer.parseInt(next()); }
          public long nextLong() { return Long.parseLong(next()); }
          public double nextDouble() { return Double.parseDouble(next()); }
      }
  
      // fast output
      static class OutputWriter {
          BufferedWriter writer;
  
          public OutputWriter(OutputStream stream) {
              writer = new BufferedWriter(new OutputStreamWriter(stream));
          }
  
          public void print(int i) throws IOException { writer.write(i); }
          public void print(String s) throws IOException { writer.write(s); }
          public void print(char[] c) throws IOException { writer.write(c); }
          public void close() throws IOException { writer.close(); }
      }
  
  
  }
  
  