description: The Olympic Games have just started and Federico is eager to watch the marathon race.
  
  There will be n athletes, numbered from 1 to n, competing in the marathon, and all of them have taken part in 5 important marathons, numbered from 1 to 5, in the past. For each 1≤ i≤ n and 1≤ j≤ 5, Federico remembers that athlete i ranked r_{i,j}-th in marathon j (e.g., r_{2,4}=3 means that athlete 2 was third in marathon 4).
  
  Federico considers athlete x superior to athlete y if athlete x ranked better than athlete y in at least 3 past marathons, i.e., r_{x,j}<r_{y,j} for at least 3 distinct values of j.
  
  Federico believes that an athlete is likely to get the gold medal at the Olympics if he is superior to all other athletes.
  
  Find any athlete who is likely to get the gold medal (that is, an athlete who is superior to all other athletes), or determine that there is no such athlete.
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases. Then t test cases follow.
  
  The first line of each test case contains a single integer n (1≤ n≤ 50 000) — the number of athletes.
  
  Then n lines follow, each describing the ranking positions of one athlete.
  
  The i-th of these lines contains the 5 integers r_{i,1},\,r_{i,2},\,r_{i,3},\,r_{i,4},  r_{i,5} (1≤ r_{i,j}≤ 50 000) — the ranking positions of athlete i in the past 5 marathons. It is guaranteed that, in each of the 5 past marathons, the n athletes have distinct ranking positions, i.e., for each 1≤ j≤ 5, the n values r_{1,j},  r_{2, j},  ...,  r_{n, j} are distinct.
  
  It is guaranteed that the sum of n over all test cases does not exceed 50 000.
  
  Output
  
  For each test case, print a single integer — the number of an athlete who is likely to get the gold medal (that is, an athlete who is superior to all other athletes). If there are no such athletes, print -1. If there is more than such one athlete, print any of them.
  
  Example
  
  Input
  
  
  4
  1
  50000 1 50000 50000 50000
  3
  10 10 20 30 30
  20 20 30 10 10
  30 30 10 20 20
  3
  1 1 1 1 1
  2 2 2 2 2
  3 3 3 3 3
  6
  9 5 3 7 1
  7 4 1 6 8
  5 6 7 3 2
  6 7 8 8 6
  4 2 2 4 5
  8 3 6 9 4
  
  
  Output
  
  
  1
  -1
  1
  5
  
  Note
  
  Explanation of the first test case: There is only one athlete, therefore he is superior to everyone else (since there is no one else), and thus he is likely to get the gold medal.
  
  Explanation of the second test case: There are n=3 athletes. 
  
    * Athlete 1 is superior to athlete 2. Indeed athlete 1 ranks better than athlete 2 in the marathons 1, 2 and 3. 
    * Athlete 2 is superior to athlete 3. Indeed athlete 2 ranks better than athlete 3 in the marathons 1, 2, 4 and 5. 
    * Athlete 3 is superior to athlete 1. Indeed athlete 3 ranks better than athlete 1 in the marathons 3, 4 and 5. 
  
  
  
  Explanation of the third test case: There are n=3 athletes. 
  
    * Athlete 1 is superior to athletes 2 and 3. Since he is superior to all other athletes, he is likely to get the gold medal. 
    * Athlete 2 is superior to athlete 3. 
    * Athlete 3 is not superior to any other athlete. 
  
  
  
  Explanation of the fourth test case: There are n=6 athletes. 
  
    * Athlete 1 is superior to athletes 3, 4, 6. 
    * Athlete 2 is superior to athletes 1, 4, 6. 
    * Athlete 3 is superior to athletes 2, 4, 6. 
    * Athlete 4 is not superior to any other athlete. 
    * Athlete 5 is superior to athletes 1, 2, 3, 4, 6. Since he is superior to all other athletes, he is likely to get the gold medal. 
    * Athlete 6 is only superior to athlete 4. 
solution: import static java.lang.Math.max;
  import static java.lang.Math.min;
  import static java.lang.Math.abs;
  import static java.lang.System.out;
  import java.util.* ;
  import java.math.*;
  import java.io.*;
  
  
   public class javaTemplate {
  	
  	public static final int M = 1000000007 ;
  	static FastReader sc = new FastReader();
  	static int N = 86028121 ;
  	static boolean globB[] = new boolean[N+1] ;
  	static int globA[] = new int[10000000] ;
  	
  	
  	public static void main(String[] args) {
  		
  int t = sc.nextInt() ;
  		
  		while(t -- != 0) {
  			int n = sc.nextInt() ;
  			Map<Integer,ArrayList<Integer>> map = new HashMap<>() ;
  			for(int i = 1 ; i< n+1 ; i++) {
  				ArrayList<Integer> list = new ArrayList<>() ;
  				for(int j = 0 ; j< 5 ; j++) {
  					list.add(sc.nextInt()) ;
  				}
  				map.put(i,list) ;
  			}
  			
  			int winner = 1 ;
  			
  			for(Map.Entry<Integer, ArrayList<Integer>> e: map.entrySet()) {
  				int x = e.getKey() ;
  				ArrayList<Integer> y = e.getValue() ;
  				ArrayList<Integer> w = map.get(winner) ;
  				if(x >=2) {
  					int c = 0 ;
  					for(int i = 0 ; i< 5 ; i++) {
  						if(w.get(i) > y.get(i)) {
  							c ++ ;
  						}
  					}
  					
  					if(c >= 3) winner = x ;
  				}
  				
  			}
  			
  			boolean found = true ;
  			for(Map.Entry<Integer, ArrayList<Integer>> e: map.entrySet()) {
  				int x = e.getKey() ;
  				ArrayList<Integer> y = e.getValue() ;
  				ArrayList<Integer> w = map.get(winner) ;
  				if(x !=winner) {
  					int c = 0 ;
  					for(int i = 0 ; i< 5 ; i++) {
  						if(w.get(i) > y.get(i)) {
  							c ++ ;
  						}
  					}
  					
  					if(c >= 3) {
  						found = false ;
  						break ;
  					}
  				}
  				
  			}
  			
  			
  			
  			
  			System.out.println(found ? winner : "-1");
  			
  			
  		}
  		
  	}
  
  
  	/*
  	 @ Observation is imp. for problem A and B
  	 1->> Read the problem properly take time to read the problem 
  	 if it is too lengthy.
  	 2->> Draw the test cases of A and B 
  	 3->> Don't over think the problem 
  	 4->> Try to take sum variable as long
  	 5->> Avoid Nested if else statement
  	 6->> If it looks like a Greedy problem try to figure out the ans. 
  	 for the smallest test case.
  	 7->> If it is a binary String check no. of 0's and 1's. 
  	 If it is a even try to pair it (may be not applicable for every questions).
  	 8->> Always check the constrains and try BruteForce
  	 @ Implement it quickly 
  	 */
  	
  
  	
  	
  	
  
  
  	
  	
  //_________________________//Template//_____________________________________________________________________
  	
  	
  		//		FAST I/O
  		static class FastReader {
  	        BufferedReader br;
  	        StringTokenizer st;
  	        
  	        public FastReader()
  	        {
  	            br = new BufferedReader(
  	                new InputStreamReader(System.in));
  	        }
  	 
  	        String next()
  	        {
  	            while (st == null || !st.hasMoreElements()) {
  	                try {
  	                    st = new StringTokenizer(br.readLine());
  	                }
  	                catch (IOException e) {
  	                    e.printStackTrace();
  	                }
  	            }
  	            return st.nextToken();
  	        }
  	 
  	        int nextInt() { return Integer.parseInt(next()); }
  	 
  	        long nextLong() { return Long.parseLong(next()); }
  	 
  	        double nextDouble()
  	        {
  	            return Double.parseDouble(next());
  	        }
  	 
  	        String nextLine()
  	        {
  	            String str = "";
  	            try {
  	                str = br.readLine();
  	            }
  	            catch (IOException e) {
  	                e.printStackTrace();
  	            }
  	            return str;
  	        }
  		}
  	
  	
  		
  		
  		
  		// Sorting
  		public static void sort(int[] arr) {
  	        //because Arrays.sort() uses quicksort which is dumb
  	        //Collections.sort() uses merge sort
  	        ArrayList<Integer> ls = new ArrayList<Integer>();
  	        for(int x: arr)
  	            ls.add(x);
  	        Collections.sort(ls);
  	        for(int i=0; i < arr.length; i++)
  	            arr[i] = ls.get(i);
  	    }
  		
  		
  		
  		
  		
  		// Modulo
  		static int mod(int a) {
  		   return (a%M + M) % M;
  		}
  		
  		
  		
  		
  		
  		
  		
  		//		Palindrom or Not
  		static boolean isPalindrome(String str, int low, int high) {
  					while (low < high) {
  						if (str.charAt(low) != str.charAt(high)) return false;
  					 	low++;
  					 	high--;
  					}
  					return true;
  				}
  	
  	
  
  	
  	
  	
  	
  	
  	
  	
  	
  		// check if sorted or not	
  		public static boolean isSorted(int[] a)
  	    {
  	        for (int i = 0; i < a.length - 1; i++)
  	        {
  	            if (a[i] > a[i + 1]) {
  	                return false;
  	            }
  	        }
  	        return true;
  	    }
  	
  	
  	
  		
  		
  	
  		// GCD
  		public static int GCD(int a , int b) {
  				if(b == 0) return a ;
  				
  				return GCD(b, a%b) ;
  			}
  	
  		
  		
  		
  		
  		// sieve
  		public static void sieve() {
  			Arrays.fill(globB, true);
  			globB[0] = false ;
  			globB[1] = false ;
  			for(int i = 2 ; i * i <= N ; i++) {
  				if(globB[i]) {
  				for(int j = i * i ; j<= N ; j+= i) {
  					globB[j] = false ;
  				 }
  				}
  			}
  			
  		}
  
  		
  		
  		
  		// fastPower
  		public static long fastPowerModulo(long a, long b, long n) {
  			long res = 1 ;
  			while(b > 0) {
  			if((b&1) != 0) {
  				res = (res * a % n) % n ;
  			}
  			a = (a % n * a % n) % n ;
  			b = b >> 1 ;
  			}
  			return res ;
  		}
  	
  		
  		
          // LCM
  		static int LCM(int a, int b)
  	    {
  	        return (a / GCD(a, b)) * b;
  	    }
  		
  
  }
  
  
   
   
   
   
   
   
  