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.*;
  
   // Author : Yash Shah
  
  public class D implements Runnable {
  
      public void run() {
  
          InputReader sc = new InputReader(System.in);
          PrintWriter out = new PrintWriter(System.out);
          
          int t = sc.nextInt();
          
          while(t--!=0) {
              int n = sc.nextInt();
              boolean z = n%2==1;
              n/=2;
              char a[] = new char[n];
              Arrays.fill(a,'a');
              out.print(a);
              if(n>0)
                  a[0] = 'b';
              out.print(a);
              out.print(z?"z":"");
              out.println();
          }
  
          out.close();
      }
   
  //========================================================================
  
  	
  	static void sa(long a[],InputReader sc)
  	{
  		for(int i=0;i<a.length;i++)
  		{
  			a[i]=sc.nextLong();
  		}
          // Arrays.sort(a);
  	}
  
  	static class pair<U extends Comparable<U>, V extends Comparable<V>> implements Comparable<pair<U, V>> {
          public U x;
          public V y;
  
          public pair(U x, V y) {
              this.x = x;
              this.y = y;
          }
  
          public int compareTo(pair<U, V> other) {
              int i = x.compareTo(other.x);
              if (i != 0) return i;
              return y.compareTo(other.y);
          }
  
          public String toString() {
              return x.toString() + " " + y.toString();
          }
  
          public boolean equals(Object obj) {
              if (this.getClass() != obj.getClass()) return false;
              pair<U, V> other = (pair<U, V>) obj;
              return x.equals(other.x) && y.equals(other.y);
          }
  
          public int hashCode() {
              return 31 * x.hashCode() + y.hashCode();
          }
  
      }
  
  
      static class InputReader {
          private InputStream stream;
          private byte[] buf = new byte[1024];
          private int curChar;
          private int numChars;
          private SpaceCharFilter filter;
          private BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
   
          public InputReader(InputStream stream) {
              this.stream = stream;
          }
         
          public int read() {
              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 nextLine() {
              String str = "";
              try {
                  str = br.readLine();
              }
              catch (IOException e) {
                  e.printStackTrace();
              }
              return str;
          }
          public int nextInt() {
              int c = read();
             
              while(isSpaceChar(c))
                  c = read();
             
              int sgn = 1;
             
              if (c == '-') {
                  sgn = -1;
                  c = read();
              }
             
              int res = 0;
              do {
                  if(c<'0'||c>'9')
                      throw new InputMismatchException();
                  res *= 10;
                  res += c - '0';
                  c = read();
              }
              while (!isSpaceChar(c));
             
              return res * sgn;
          }
         
          public long nextLong() {
              int c = read();
              while (isSpaceChar(c))
                  c = read();
              int sgn = 1;
              if (c == '-') {
                  sgn = -1;
                  c = read();
              }
              long res = 0;
             
              do {
                  if (c < '0' || c > '9')
                      throw new InputMismatchException();
                  res *= 10;
                  res += c - '0';
                  c = read();
              }
              while (!isSpaceChar(c));
                  return res * sgn;
          }
         
          public double nextDouble() {
              int c = read();
              while (isSpaceChar(c))
                  c = read();
              int sgn = 1;
              if (c == '-') {
                  sgn = -1;
                  c = read();
              }
              double res = 0;
              while (!isSpaceChar(c) && c != '.') {
                  if (c == 'e' || c == 'E')
                      return res * Math.pow(10, nextInt());
                  if (c < '0' || c > '9')
                      throw new InputMismatchException();
                  res *= 10;
                  res += c - '0';
                  c = read();
              }
              if (c == '.') {
                  c = read();
                  double m = 1;
                  while (!isSpaceChar(c)) {
                      if (c == 'e' || c == 'E')
                          return res * Math.pow(10, nextInt());
                      if (c < '0' || c > '9')
                          throw new InputMismatchException();
                      m /= 10;
                      res += (c - '0') * m;
                      c = read();
                  }
              }
              return res * sgn;
          }
         
          public String readString() {
              int c = read();
              while (isSpaceChar(c))
                  c = read();
              StringBuilder res = new StringBuilder();
              do {
                  res.appendCodePoint(c);
                  c = read();
              }
              while (!isSpaceChar(c));
             
              return res.toString();
          }
       
          public boolean isSpaceChar(int c) {
              if (filter != null)
                  return filter.isSpaceChar(c);
              return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
          }
       
          public String next() {
              return readString();
          }
         
          public interface SpaceCharFilter {
              public boolean isSpaceChar(int ch);
          }
      }
  
      public static void main(String args[]) throws Exception {
          new Thread(null, new D(),"Main",1<<27).start();
      }
  }
  