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: 
   
   //   * * * the goal is to be worlds best * * *   //
   import java.io.BufferedReader;
   import java.io.IOException;
   import java.io.InputStreamReader;
   import java.util.*;
    
   
   public class E {
       static class Pair implements Comparable<Pair>{
           int a;
           int b;
   
           Pair(int a , int b){
               this.a = a;
               this.b = b;
           }
   
           public int compareTo(Pair o){
               return this.a - o.a;
           }
       }
   
   //==================================================================================================
   
       public static void main(String[] args) {
          FastScanner sc = new FastScanner();
          int t = sc.nextInt();
          while(t-->0){
              int n = sc.nextInt();
              if(n == 1){
                  System.out.println("a");
                  continue;
              }
              StringBuilder sb = new StringBuilder("");
              for(int i = 0; i < n / 2; i++){
                  sb.append("a");
              }
              sb.append("b");
              for(int i = 0; i < n / 2 - 1; i++){
                  sb.append("a");
              }
              if((n & 1) == 1){
                  sb.append("c");
              }
              
              System.out.println(sb.toString());
          }
       }
   
   //==================================================================================================
   
   
       // Use this instead of Arrays.sort() on an array of ints. Arrays.sort() is n^2
       // worst case since it uses a version of quicksort. Although this would never
       // actually show up in the real world, in codeforces, people can hack, so
       // this is needed. 
  	 static void sort(int[] arr) {
  		 int n = arr.length;
  		 ArrayList<Integer> res = new ArrayList<>();
  		 for (int a : arr) {
  		 	 res.add(a);
  		 }
  		 Collections.sort(res);
  		 for (int i = 0; i < n; i++) {
  			 arr[i] = res.get(i);
  		 }
  	 }
   
  	 static void sort(long[] arr) {
  		 int n = arr.length;
  		 ArrayList<Long> res = new ArrayList<>();
  		 for (long a : arr) {
  			 res.add(a);
  		 }
  		 Collections.sort(res);
  		 for (int i = 0; i < n; i++) {
  			 arr[i] = res.get(i);
  		} 
  	 }
   
  	 static void revSort(int[] arr) {
  		 int n = arr.length;
  		 ArrayList<Integer> res = new ArrayList<>();
  		 for (int a : arr) {
  			 res.add(a);
  		 }
  		 Collections.sort(res, Collections.reverseOrder());
  		 for (int i = 0; i < n; i++) {
  			 arr[i] = res.get(i);
  		 }
  	 } 
       
       // Use this to input code since it is faster than a Scanner
       static class FastScanner {
           BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
           StringTokenizer st=new StringTokenizer("");
           String next() {
               while (!st.hasMoreTokens())
                   try {
                       st=new StringTokenizer(br.readLine());
                   } catch (IOException e) {
                       e.printStackTrace();
                   }
               return st.nextToken();
           }
           
           int nextInt() {
               return Integer.parseInt(next());
           }
   
           double nextDouble() {
               return Double.parseDouble(next());
           }
    
           String str = "";
    
           String nextLine() {
               try {
                   str = br.readLine();
               } catch (IOException e) {
                   e.printStackTrace();
               }
               return str;
           }
    
           int[] readArray(int n) {
               int[] a = new int[n];
               for (int i = 0; i < n; i++)
                   a[i] = nextInt();
               return a;
           }
    
           long[] readLongArray(int n) {
               long[] a = new long[n];
               for (int i = 0; i < n; i++)
                   a[i] = nextLong();
               return a;
           }
           long nextLong() {
               return Long.parseLong(next());
           }
       }
       
       // print integers in array
       static void print(int a[]){
           for(int e : a){
               System.out.print(e + " ");
           }
           System.out.println();
       }
  
       static void print(long a[]){
           for(long e : a){
               System.out.print(e + " ");
           }
           System.out.println();
       }
  
       // generates all the prime numbers upto n
       static void sieveOfEratosthenes(int n , ArrayList<Integer> al)
       {
           boolean prime[] = new boolean[n + 1];
           for (int i = 0; i <= n; i++)
               prime[i] = true;
    
           for (int p = 2; p * p <= n; p++) 
           {
               if (prime[p] == true) 
               {
                   for (int i = p * p; i <= n; i += p)
                       prime[i] = false;
               }
           }
           for (int i = 2; i <= n; i++)
           {
               if (prime[i] == true)
                   al.add(i);
           }
       }
       static final int mod = 1000_000_000 + 7;
       static final int imx = Integer.MAX_VALUE;
       static final int imi = Integer.MIN_VALUE;
       
  	 static ArrayList<Integer> divisors(int n) {
  		 ArrayList<Integer> al = new ArrayList<>();
  		 for (int i = 1; i * i <= n; i++) {
  			 if (n % i == 0) {
  				 if (n == i * i) {
  					 al.add(i);
  				 } else {
  					 al.add(i);
  					 al.add(n / i);
  				 }
  		 	 }
  		 }
  		 Collections.sort(al);
  		 return al;
  	 }
   
  	 static int countDigits(int n) {
  		 int c = 0;
  		 while (n != 0) {
  			 c++;
  			 n /= 10;
  		 }
  		 return c;
  	 }
   
  	 static boolean palindrome(String str) {
  		 int s = 0;
  		 int e = str.length() - 1;
  		 while (s < e) {
  			 if (str.charAt(s) != str.charAt(e)) {
  				 return false;
  			 }
  			 s++;
  			 e--;
  		 }
  		 return true;
  	 }
   
  	 static void reverse(int[] arr, int s, int e) {
  		 while (s < e) {
  			 int temp = arr[s];
  			 arr[s++] = arr[e];
  			 arr[e--] = temp;
  		 }
  	 }
       // starting exclusive ending inclusive
  	 static int getMax(int[] arr, int s, int e) {
  		 int maxi = s;
  		 for (int i = s + 1; i <= e; i++) {
  			 if (arr[i] > arr[maxi]) {
  				 maxi = i;
  			 }
  		 }
  		 return maxi;
  	 }
  
       // starting exclusive ending inclusive
       static int getMin(int[] arr, int s, int e) {
  	     int mini = s;
  		 for (int i = s + 1; i <= e; i++) {
  			 if (arr[i] < arr[mini]) {
  				 mini = i;
  			 }
  		 }
  		 return mini;
  	 }
   
  	 static long lcm(long n1, long n2) {
  		 return (n1 * n2) / gcd(n1, n2);
   	 }
   
  	 static int lcm(int n1, int n2) {
  		 return (n1 * n2) / gcd(n1, n2);
  	 }
   
  	 static long gcd(long num1, long num2) {
  		 if (num2 == 0) {
  			 return num1;
  		 }
  		 return gcd(num2, num1 % num2);
  	 }
   
  	 static int gcd(int num1, int num2) {
  		 if (num2 == 0) {
  			 return num1;
  		 }
  		 return gcd(num2, num1 % num2);
  	 }
  
       //fastPow
       static long fastPow(long base, long exp) {
           if (exp==0) return 1;
           long half=fastPow(base, exp/2);
           if (exp%2==0) return mul(half, half);
           return mul(half, mul(half, base));
       }
   
       // multiply two long numbers % mod
       static long mul(long a, long b) {
           return a*b%mod;
       }
   
       static int nCr(int n, int r)
       {
          return factorial(n) / (factorial(r) *
              factorial(n - r));
       }
       
       // Returns factorial of n
       static int factorial(int n)
       {
           int res = 1;
           for (int i = 2; i <= n; i++)
               res = res * i;
           return res;
       }
        
       // to generate the lps array
       // lps means longest preffix that is also a suffix
       static void generateLPS(int lps[] , String p){
           int l = 0;
           int r = 1;
      
           while(l < p.length() && l < r && r < p.length()){
               if(p.charAt(l) == p.charAt(r)){
                   lps[r] = l + 1;
                   l++;
                   r++;
               }
               else{
                   if(l > 0)
                       l = lps[l - 1];
                   else
                       r++;    
               }
           }
       }
        
       // returns the index of the element which is just smaller than or
       // equal to the tar in the given arraylist 
       static int lowBound(ArrayList<Integer> ll,long tar ,int l,int r){
           if(l>r) return l;
   
           int mid=l+(r-l)/2;
   
           if(ll.get(mid)>=tar){
               return lowBound(ll,tar,l,mid-1);
           }
   
           return lowBound(ll,tar,mid+1,r);
       }
   
       // returns the index of the element which is just greater than or
       // equal to the tar in the given arraylist 
       static int upBound(ArrayList<Integer> ll,long tar,int l ,int r){
           if(l>r) return l;
   
           int mid=l+(r-l)/2;
   
           if(ll.get(mid)<=tar){
               return upBound(ll,tar,mid+1 ,r);
           }
   
           return upBound(ll,tar,l,mid-1);
       }
   
       static void swap(int a[] , int i , int j){
           int x = a[i];
           int y = a[j];
           a[j] = x;
           a[i] = y;
       }
       static void swap(long a[] , int i , int j){
           long x = a[i];
           long y = a[j];
           a[j] = x;
           a[i] = y;
      }
       // a -> z == 97 -> 122
   
       // String.format("%.9f", ans) ,--> to get upto 9 decimal places , (ans is double)
       
       // write 
   }
   