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: //package Div2.C;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  public class SetOrDecrease {
      public static void main(String[] args) throws IOException {
          BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
          int t = Integer.parseInt(br.readLine());
          while(t>0){
              String []nk=br.readLine().split(" ");
              int n=Integer.parseInt(nk[0]);
              long k=Long.parseLong(nk[1]);
              String []str=br.readLine().split(" ");
              List<Integer> list=new ArrayList<>();
              for(int i=0;i<n;i++)
                  list.add(Integer.parseInt(str[i]));
              Collections.sort(list);
              long sum=0;
              for(int i=0;i<n;i++)
                  sum+=list.get(i);
              if(sum<=k)
                  System.out.println(0);
              else {
                  long minSteps = sum - k;
                  long drop=0;
                  long targetDrop = sum-k;
                  for (int i = n - 1; i > 0; i--) {
                      //assignment at ith element
                      drop += list.get(i) - list.get(0);
                      if (drop >= targetDrop) {
                          if (minSteps > n - i)
                              minSteps = n - i;
                      } else {
                          long diff = targetDrop - drop;
                          long div = diff / (n - i + 1);
                          long rem = diff % (n - i + 1);
                          long steps = rem > 0 ? (div + 1) + n - i : div + n - i;
                          if (minSteps > steps)
                              minSteps = steps;
  
                      }
                  }
                  System.out.println(minSteps);
              }
              t--;
          }
      }
  }
  