description: You are given an integer array a_1, a_2, ..., a_n and integer k.
  
  In one step you can 
  
    * either choose some index i and decrease a_i by one (make a_i = a_i - 1); 
    * or choose two indices i and j and set a_i equal to a_j (make a_i = a_j). 
  
  
  
  What is the minimum number of steps you need to make the sum of array ∑_{i=1}^{n}{a_i} ≤ k? (You are allowed to make values of array negative).
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 10^4) — the number of test cases.
  
  The first line of each test case contains two integers n and k (1 ≤ n ≤ 2 ⋅ 10^5; 1 ≤ k ≤ 10^{15}) — the size of array a and upper bound on its sum.
  
  The second line of each test case contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9) — the array itself.
  
  It's guaranteed that the sum of n over all test cases doesn't exceed 2 ⋅ 10^5.
  
  Output
  
  For each test case, print one integer — the minimum number of steps to make ∑_{i=1}^{n}{a_i} ≤ k.
  
  Example
  
  Input
  
  
  4
  1 10
  20
  2 69
  6 9
  7 8
  1 2 1 3 1 2 1
  10 1
  1 2 3 1 2 6 1 6 8 10
  
  
  Output
  
  
  10
  0
  2
  7
  
  Note
  
  In the first test case, you should decrease a_1 10 times to get the sum lower or equal to k = 10.
  
  In the second test case, the sum of array a is already less or equal to 69, so you don't need to change it.
  
  In the third test case, you can, for example: 
  
    1. set a_4 = a_3 = 1; 
    2. decrease a_4 by one, and get a_4 = 0. 
  
  As a result, you'll get array [1, 2, 1, 0, 1, 2, 1] with sum less or equal to 8 in 1 + 1 = 2 steps.
  
  In the fourth test case, you can, for example: 
  
    1. choose a_7 and decrease in by one 3 times; you'll get a_7 = -2; 
    2. choose 4 elements a_6, a_8, a_9 and a_{10} and them equal to a_7 = -2. 
  
  As a result, you'll get array [1, 2, 3, 1, 2, -2, -2, -2, -2, -2] with sum less or equal to 1 in 3 + 4 = 7 steps.
solution: import java.io.*;
  import java.util.*;
  
  public class new1{
  	
  
  	public static void main(String[] args)  throws IOException{
      	BufferedWriter output = new BufferedWriter(new OutputStreamWriter(System.out));
  		FastReader s = new FastReader();
  	
  		int t = s.nextInt();
      	for(int z = 0; z < t; z++) {
      		int n = s.nextInt();
      		long k = s.nextLong();
      		long sum = 0;
      		ArrayList<Long> aList = new ArrayList<Long>();
      		for(int i = 0; i < n; i++) {
      			long vv= s.nextLong();
      			aList.add(vv);
      			sum = sum + vv;
      		}
      		if(sum <= k) {
      			System.out.println(0);
      			continue;
      		}
      		aList.sort(null);
      		aList.add(aList.get(0)); int count = 0;
      		//System.out.println(aList.toString());
      		long ans = Long.MAX_VALUE;
      		for(int i = n ; i >= 1; i--) {
      			sum = sum - aList.get(i);
      			count++;
      			long aa = (k - sum) / count;
      			if(k < sum && (sum - k) % count != 0) aa = aa - 1;
      			aa = Math.min(aa, aList.get(n));
      			int c1 = count - 1;
      			long steps = aList.get(n) - aa + c1;
      			ans = Math.min(steps, ans);
      			//System.out.println(steps + " " + sum);
      		}
      		if(ans < 0) System.out.println(0);
      		else System.out.println(ans);
      		//System.out.println(Math.floorDiv(-3, 2));
      		
      		
      		
      		
      		
      		
      	}
      	//output.flush();
  
      }
  }
  
  
  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();
      }
   
      public 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;
  }}