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.OutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.PrintWriter;
  import java.util.*;
  import java.io.IOException;
  import java.io.BufferedReader;
  import java.io.InputStreamReader;
  import java.io.InputStream;
  
  public class Main {
  
      public static void main(String[] args) {
          InputStream inputStream = System.in;
          OutputStream outputStream = System.out;
          InputReader in = new InputReader(inputStream);
          PrintWriter out = new PrintWriter(outputStream);
          TaskA solver = new TaskA();
          int t;
          t = in.nextInt();
          //t = 1;
          while (t > 0) {
              solver.call(in,out);
              t--;
          }
          out.close();
      }
  
      static class TaskA {
          public void call(InputReader in, PrintWriter out) {
              int n;
              long k;
              n = in.nextInt();
              k = in.nextLong();
              long[] arr = new long[n];
              long sum = 0;
              for (int i = 0; i < n; i++) {
                  arr[i] = in.nextLong();
                  sum += arr[i];
              }
              sort(arr);
              if(sum <= k){
                  out.println(0);
                  return;
              }
              long[] prefix = new long[n];
              for (int i = 1; i < n; i++) {
                  prefix[i] = prefix[i-1] + arr[i];
              }
              long ans = Long.MAX_VALUE, a, b;
              for (int i = n - 1; i >= 0; i--) {
                  a = (k - prefix[i])/ ((long)n - (long)i);
                  b = 0;
                  if(a > arr[0]){
                      a = arr[0];
                  }
                  while(true){
                      if (prefix[i] + a * ((long) n - (long)i) <= k)
                          ans = Math.min(ans, (Math.abs(arr[0] - a)) + ((long)n - 1L - (long) i));
                      a--;
                      b++;
                      if(b >= 50){
                          break;
                      }
                  }
              }
              out.println(ans);
  
          }
      }
  
      static int gcd(int a, int b)
      {
          if (a == 0)
              return b;
          return gcd(b % a, a);
      }
  
      static int lcm(int a, int b)
      {
          return (a / gcd(a, b)) * b;
      }
  
      static class answer implements Comparable<answer>{
          int a, b;
  
          public answer(int a, int b) {
              this.a = a;
              this.b = b;
          }
  
          @Override
          public int compareTo(answer o) {
              return this.a - o.a;
          }
      }
  
      static class arrayListClass {
          ArrayList<Integer> arrayList2 ;
  
          public arrayListClass(ArrayList<Integer> arrayList) {
              this.arrayList2 = arrayList;
          }
      }
  
      static long gcd(long a, long b)
      {
          if (b == 0)
              return a;
          return gcd(b, a % b);
      }
  
      static void sort(long[] a) {
          ArrayList<Long> l=new ArrayList<>();
          for (long i:a) l.add(i);
          Collections.sort(l);
          for (int i=0; i<a.length; i++) a[i]=l.get(i);
      }
  
      static final Random random=new Random();
  
      static void shuffleSort(int[] a) {
          int n = a.length;
          for (int i=0; i<n; i++) {
              int oi=random.nextInt(n), temp=a[oi];
              a[oi]=a[i]; a[i]=temp;
          }
          Arrays.sort(a);
      }
  
      static class InputReader {
          public BufferedReader reader;
          public StringTokenizer tokenizer;
  
          public InputReader(InputStream stream) {
              reader = new BufferedReader(new InputStreamReader(stream), 32768);
              tokenizer = null;
          }
  
          public String next() {
              while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                  try {
                      tokenizer = new StringTokenizer(reader.readLine());
                  } catch (IOException e) {
                      throw new RuntimeException(e);
                  }
              }
              return tokenizer.nextToken();
          }
  
          public int nextInt() {
              return Integer.parseInt(next());
          }
          public long nextLong(){
              return Long.parseLong(next());
          }
          public double nextDouble() {
              return Double.parseDouble(next());
          }
  
      }
  }