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.util.*;
  import java.io.*;
  public class daine {
     
  	static Scanner sc=new Scanner(System.in);
  	static PrintWriter pw=new PrintWriter(System.out);
  	
  	public static void main(String[] args) throws IOException, InterruptedException{
      int t=sc.nextInt();
  	while(t-->0) {
  		int n=sc.nextInt();
  		if(n%2==0) {
  			int x=n/2;
  			for(int i=0;i<x;i++)
  				pw.print("a");
  			pw.print("b");
  			for(int i=0;i<x-1;i++)
  				pw.print("a");
  			pw.println();
  		}
  		else {
  			int x=n/2;
  			for(int i=0;i<x;i++)
  				pw.print("a");
  		if(n!=1)	pw.print("b");
  			for(int i=0;i<x-1;i++)
  				pw.print("a");
  			pw.println("z");
  		}
  	}
  		
  		
  	pw.flush();
  	}
  	static class pair{
  		int x;
  		int y;
  		public pair(int a,int b) {
  			this.x=a;this.y=b;
  		}
  		public void swap(pair p) {
  			pair temp=new pair(p.x, p.y);
  			p.x=this.x;p.y=this.y;
  			this.x=temp.x;this.y=temp.y;
  		}
  		public String toString () {
  			return x+","+y+" ";
  		}
  		
  		public boolean equals(pair p) {
  			if(x==p.x && y==p.y)
  				return true;
  			return false;
  		}
  	}
  	static class PairPoint{
  		pair p1;
  		pair p2;
  		public PairPoint(pair p1,pair p2) {
  			this.p1=p1;
  			this.p2=p2;
  			
  		}
          public boolean inter(pair p) {
          	int x1=Math.max(p1.x, p2.x),x2=Math.min(p1.x, p2.x);
          	int y1=Math.max(p1.y, p2.y),y2=Math.min(p1.y, p2.y);
          	if((p.x>=x2 && p.x<=x1) && (p.y>=y2 && p.y<=y1))
          		return true;
          	return false;
   		}
  		public void swap(PairPoint pp) {
  			pp.p1.swap(this.p1);
  			pp.p2.swap(this.p2);
  		}
  		
  		public String toString () {
  			return p1.toString()+p2.toString();
  		}
  		public boolean equals (PairPoint pp) {
  			if(p1.equals(pp.p1) && p2.equals(pp.p2))
  				return true;
  			return false;
  		}
  	}
  	static class Scanner {
  		StringTokenizer st;
  		BufferedReader br;
   
  		public Scanner(InputStream s) {
  			br = new BufferedReader(new InputStreamReader(s));
  		}
   
  		public Scanner(FileReader r) {
  			br = new BufferedReader(r);
  		}
   
  		public String next() throws IOException {
  			while (st == null || !st.hasMoreTokens())
  				st = new StringTokenizer(br.readLine());
  			return st.nextToken();
  		}
   
  		public int nextInt() throws IOException {
  			return Integer.parseInt(next());
  		}
   
  		public long nextLong() throws IOException {
  			return Long.parseLong(next());
  		}
   
  		public String nextLine() throws IOException {
  			return br.readLine();
  		}
   
  		public double nextDouble() throws IOException {
  			String x = next();
  			StringBuilder sb = new StringBuilder("0");
  			double res = 0, f = 1;
  			boolean dec = false, neg = false;
  			int start = 0;
  			if (x.charAt(0) == '-') {
  				neg = true;
  				start++;
  			}
  			for (int i = start; i < x.length(); i++)
  				if (x.charAt(i) == '.') {
  					res = Long.parseLong(sb.toString());
  					sb = new StringBuilder("0");
  					dec = true;
  				} else {
  					sb.append(x.charAt(i));
  					if (dec)
  						f *= 10;
  				}
  			res += Long.parseLong(sb.toString()) / f;
  			return res * (neg ? -1 : 1);
  		}
   
  		public long[] nextlongArray(int n) throws IOException {
  			long[] a = new long[n];
  			for (int i = 0; i < n; i++)
  				a[i] = nextLong();
  			return a;
  		}
   
  		public Long[] nextLongArray(int n) throws IOException {
  			Long[] a = new Long[n];
  			for (int i = 0; i < n; i++)
  				a[i] = nextLong();
  			return a;
  		}
   
  		public int[] nextIntArray(int n) throws IOException {
  			int[] a = new int[n];
  			for (int i = 0; i < n; i++)
  				a[i] = nextInt();
  			return a;
  		}
   
  		public Integer[] nextIntegerArray(int n) throws IOException {
  			Integer[] a = new Integer[n];
  			for (int i = 0; i < n; i++)
  				a[i] = nextInt();
  			return a;
  		}
   
  		public boolean ready() throws IOException {
  			return br.ready();
  		}
   
  	}
  }