using System.CodeDom.Compiler; using System.Collections.Generic; using System.Collections; using System.ComponentModel; using System.Diagnostics.CodeAnalysis; using System.Globalization; using System.IO; using System.Linq; using System.Reflection; using System.Runtime.Serialization; using System.Text.RegularExpressions; using System.Text; using System;

class Result {

/*
 * Complete the 'equal' function below.
 *
 * The function is expected to return an INTEGER.
 * The function accepts INTEGER_ARRAY arr as parameter.
 */

private static int GetDistributionGap(int largestDistribution, int smallestDistribution) {
    var gap = (largestDistribution - smallestDistribution);

    if (gap >= 5) {
        return 5;
    }

    if (gap >= 2) {
        return 2;
    }

    return 1;
}

public static int equal(List<int> arr, int operations = 0)
{   
    var newDistributions = new List<int>(arr);
    var nextOperations = operations;

    var largestDistribution = arr.Max();
    var smallestDistribution = arr.Min();

    if (AnyDifferent(arr)) {    
        nextOperations = nextOperations + 1;

        // var largestDistribution = arr.Max();
        // var smallestDistribution = arr.Min();

        var requiredDistribution = GetDistributionGap(largestDistribution, smallestDistribution);

        for(int i = 0; i < arr.Count(); i++) {
            var leftValue = arr[i];
            if (leftValue < largestDistribution) {
                newDistributions[i] = leftValue + requiredDistribution;
            }
        }
    }

    if (nextOperations != operations) {
        return equal(newDistributions, nextOperations);
    }

    Console.WriteLine($"Iteration: {nextOperations}, Largest: {largestDistribution}, Smallest: {smallestDistribution}, Arr: {string.Join(", ", newDistributions)}");
    return nextOperations;
}

public static bool AnyDifferent(List<int> arr) {
    for(int i = 0; i < arr.Count; i++) {
        var comparable = arr[0];
        if (comparable != arr[i]) {
            return true;
        }
    }

    return false;
}

}

class Solution { public static void Main(string[] args) { TextWriter textWriter = new StreamWriter(@System.Environment.GetEnvironmentVariable("OUTPUT_PATH"), true);

    int t = Convert.ToInt32(Console.ReadLine().Trim());

    for (int tItr = 0; tItr < t; tItr++)
    {
        int n = Convert.ToInt32(Console.ReadLine().Trim());

        List<int> arr = Console.ReadLine().TrimEnd().Split(' ').ToList().Select(arrTemp => Convert.ToInt32(arrTemp)).ToList();

        int result = Result.equal(arr);

        textWriter.WriteLine(result);
    }

    textWriter.Flush();
    textWriter.Close();
}

}