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.OutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.PrintWriter;
  import java.util.InputMismatchException;
  import java.io.IOException;
  import java.io.InputStream;
  
  /**
   * Built using CHelper plug-in
   * Actual solution is at the top
   */
  public class Main {
      public static void main(String[] args) {
          InputStream inputStream = System.in;
          OutputStream outputStream = System.out;
          InputReader in = new InputReader(inputStream);
          PrintWriter out = new PrintWriter(outputStream);
          DDiana solver = new DDiana();
          int testCount = Integer.parseInt(in.next());
          for (int i = 1; i <= testCount; i++)
              solver.solve(i, in, out);
          out.close();
      }
  
      static class DDiana {
          final int M = 'z' - 'a' + 1;
  
          public void solve(int testNumber, InputReader in, PrintWriter out) {
              int n = in.nextInt();
              if (n <= M) {
                  for (int i = 0; i < Math.min(n, M); i++) {
                      out.print((char) ('a' + i));
                  }
                  out.println();
                  return;
              }
              if (n % 2 == 0) {
                  int f = (n - 1) / 2;
                  for (int i = 0; i < f; i++) {
                      out.print('a');
                  }
                  out.print('b');
                  for (int i = 0; i < f + 1; i++) {
                      out.print('a');
                  }
              } else {
                  int f = (n - 2) / 2;
                  for (int i = 0; i < f; i++) {
                      out.print('a');
                  }
                  out.print("bc");
                  for (int i = 0; i < f + 1; i++) {
                      out.print('a');
                  }
              }
              out.println();
          }
  
      }
  
      static class InputReader {
          private static final int BUFFER_LENGTH = 1 << 10;
          private InputStream stream;
          private byte[] buf = new byte[BUFFER_LENGTH];
          private int curChar;
          private int numChars;
  
          public InputReader(InputStream stream) {
              this.stream = stream;
          }
  
          private int nextC() {
              if (numChars == -1) {
                  throw new InputMismatchException();
              }
              if (curChar >= numChars) {
                  curChar = 0;
                  try {
                      numChars = stream.read(buf);
                  } catch (IOException e) {
                      throw new InputMismatchException();
                  }
                  if (numChars <= 0)
                      return -1;
              }
              return buf[curChar++];
          }
  
          public String next() {
              int c = nextC();
              while (isSpaceChar(c)) {
                  c = nextC();
              }
              StringBuilder res = new StringBuilder();
              do {
                  res.append((char) c);
                  c = nextC();
              } while (!isSpaceChar(c));
              return res.toString();
          }
  
          public int nextInt() {
              int c = skipWhileSpace();
              int sgn = 1;
              if (c == '-') {
                  sgn = -1;
                  c = nextC();
              }
              int res = 0;
              do {
                  if (c < '0' || c > '9') {
                      throw new InputMismatchException();
                  }
                  res *= 10;
                  res += c - '0';
                  c = nextC();
              } while (!isSpaceChar(c));
              return res * sgn;
          }
  
          public int skipWhileSpace() {
              int c = nextC();
              while (isSpaceChar(c)) {
                  c = nextC();
              }
              return c;
          }
  
          public boolean isSpaceChar(int c) {
              return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
          }
  
      }
  }
  
  