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.*;
  public class Diane {
      static class InputReader {
          private static final int DEFAULT_BUFFER_SIZE = 1 << 16; // Change this to increase your input size //
          private static final InputStream DEFAULT_STREAM = System.in;private static final int MAX_DECIMAL_PRECISION = 21;private int c;private byte[] buf;
          private int bufferSize, bufIndex, numBytesRead;private InputStream stream;private static final byte EOF = -1;private static final byte NEW_LINE = 10;
          private static final byte CARRIAGE_RETURN = 13;private static final byte SPACE = 32;private static final byte DASH = 45;private static final byte DOT = 46;
          private char[] charBuffer;private static byte[] bytes = new byte[58];private static int[] ints = new int[58];private static char[] chars = new char[128];
          static { char ch = ' ';int value = 0;byte _byte = 0;for (int i = 48; i < 58; i++) bytes[i] = _byte++;for (int i = 48; i < 58; i++) ints[i] = value++;for (int i = 32; i < 128; i++) chars[i] = ch++; }
          public InputReader() { this(DEFAULT_STREAM, DEFAULT_BUFFER_SIZE); }public InputReader(int bufferSize) { this(DEFAULT_STREAM, bufferSize); }public InputReader(InputStream stream) { this(stream, DEFAULT_BUFFER_SIZE); }
          public InputReader(InputStream stream, int bufferSize) { if (stream == null || bufferSize <= 0) throw new IllegalArgumentException();buf = new byte[bufferSize];charBuffer = new char[128];this.bufferSize = bufferSize;this.stream = stream; }
          private byte read() throws IOException { if (numBytesRead == EOF) throw new IOException();if (bufIndex >= numBytesRead) { bufIndex = 0;numBytesRead = stream.read(buf);if (numBytesRead == EOF) return EOF; }return buf[bufIndex++]; }
          private int readJunk(int token) throws IOException { if (numBytesRead == EOF) return EOF;do { while (bufIndex < numBytesRead) { if (buf[bufIndex] > token) return 0;bufIndex++; }numBytesRead = stream.read(buf);if (numBytesRead == EOF) return EOF;bufIndex = 0; } while (true); }
          public byte nextByte() throws IOException {return (byte) ni(); }
          public int ni() throws IOException { if (readJunk(DASH - 1) == EOF) throw new IOException();int sgn = 1, res = 0;c = buf[bufIndex];if (c == DASH) { sgn = -1;bufIndex++; } do { while (bufIndex < numBytesRead)
          { if (buf[bufIndex] > SPACE) { res = (res << 3) + (res << 1);res += ints[buf[bufIndex++]]; } else { bufIndex++;return res * sgn; } }numBytesRead = stream.read(buf);if (numBytesRead == EOF) return res * sgn;bufIndex = 0; } while (true); }
          public long nl() throws IOException { if (readJunk(DASH - 1) == EOF) throw new IOException();int sgn = 1;long res = 0L;c = buf[bufIndex];if (c == DASH) { sgn = -1;bufIndex++; } do { while (bufIndex < numBytesRead)
          { if (buf[bufIndex] > SPACE) { res = (res << 3) + (res << 1);res += ints[buf[bufIndex++]]; } else { bufIndex++;return res * sgn; } }numBytesRead = stream.read(buf);if (numBytesRead == EOF) return res * sgn;bufIndex = 0; } while (true); }
          private void doubleCharBufferSize() { char[] newBuffer = new char[charBuffer.length << 1];for (int i = 0; i < charBuffer.length; i++) newBuffer[i] = charBuffer[i];charBuffer = newBuffer; }
          public String nli() throws IOException { try { c = read(); } catch (IOException e) { return null; }if (c == NEW_LINE) return "";
              if (c == EOF) return null;int i = 0;charBuffer[i++] = (char) c;do { while (bufIndex < numBytesRead) { if (buf[bufIndex] != NEW_LINE && buf[bufIndex] != CARRIAGE_RETURN)
              { if (i == charBuffer.length) doubleCharBufferSize();charBuffer[i++] = (char) buf[bufIndex++]; } else { if(buf[bufIndex] == CARRIAGE_RETURN) bufIndex++;bufIndex++;
                  return new String(charBuffer, 0, i); } }numBytesRead = stream.read(buf);if (numBytesRead == EOF) return new String(charBuffer, 0, i);bufIndex = 0; } while (true); }
          public String ns() throws IOException { if (numBytesRead == EOF) return null;if (readJunk(SPACE) == EOF) return null;for (int i = 0; ; )
          { while (bufIndex < numBytesRead) { if (buf[bufIndex] > SPACE) { if (i == charBuffer.length) doubleCharBufferSize();charBuffer[i++] = (char) buf[bufIndex++]; }
          else {bufIndex++;return new String(charBuffer, 0, i); } }numBytesRead = stream.read(buf);if (numBytesRead == EOF) return new String(charBuffer, 0, i);bufIndex = 0; } }
          public double nd() throws IOException { String doubleVal = ns();if (doubleVal == null) throw new IOException();return Double.valueOf(doubleVal); }
          public void close() throws IOException {stream.close(); }
      }
  
      // region variables
      static InputReader sc = new InputReader();
      static OutputStream outputStream = System.out;
      static PrintWriter w = new PrintWriter(outputStream);
      // endregion
  
      private static void initiateIO()
              throws IOException {if (System.getProperty("ONLINE_JUDGE") == null) {
          try { w = new PrintWriter("output.txt");
              sc = new InputReader(new FileInputStream("input.txt"));
          } catch (Exception e) { throw new IOException(); }} }
  
      public static void main(String[] args)
              throws IOException {
  
          initiateIO();
  
          int t = sc.ni();
          while(t-- > 0)
              solve();
  
          w.close();
  
      }
  
      static void solve() throws IOException {
          int n = sc.ni();
          StringBuilder sb = new StringBuilder();
          if((n&1)==1) {
              if(n == 1) {
                  sb.append('a');
                  w.println(sb);
                  return;
              }
              int q = (n-2)/2;
              for(int i = 0; i < q; i++) {
                  sb.append('a');
              }
              sb.append("bc");
              for(int i = 0; i <= q; i++) {
                  sb.append('a');
              }
              w.println(sb);
          } else {
              if(n == 2) {
                  sb.append("ab");
                  w.println(sb);
                  return;
              }
              int q = (n-1)/2;
              for(int i = 0; i < q; i++) {
                  sb.append('a');
              }
              sb.append('b');
              for(int i = 0; i <= q; i++) {
                  sb.append('a');
              }
              w.println(sb);
          }
      }
  }