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 B {
      //--------------------------INPUT READER---------------------------------//
      static class fs {
          public BufferedReader br;
          StringTokenizer st = new StringTokenizer("");
  
          public fs() { this(System.in); }
          public fs(InputStream is) {
              br = new BufferedReader(new InputStreamReader(is));
          }
          String next() {
              while (!st.hasMoreTokens()) {
                  try { st = new StringTokenizer(br.readLine()); }
                  catch (IOException e) { e.printStackTrace(); }
              }
              return st.nextToken();
          }
  
          int ni() { return Integer.parseInt(next()); }
          long nl() { return Long.parseLong(next()); }
          double nd() { return Double.parseDouble(next()); }
          String ns() { return next(); }
  
          int[] na(long nn) {
              int n = (int) nn;
              int[] a = new int[n];
              for (int i = 0; i < n; i++) a[i] = ni();
              return a;
          }
  
          long[] nal(long nn) {
              int n = (int) nn;
              long[] l = new long[n];
              for(int i = 0; i < n; i++) l[i] = nl();
              return l;
          }
      }
      //-----------------------------------------------------------------------//
  
      //---------------------------PRINTER-------------------------------------//
      static class Printer {
          static PrintWriter w;
          public Printer() {this(System.out);}
          public Printer(OutputStream os) {
              w = new PrintWriter(os);
          }
          public void p(int i) {w.println(i);}
          public void p(long l) {w.println(l);}
          public void p(double d) {w.println(d);}
          public void p(String s) { w.println(s);}
          public void pr(int i) {w.print(i);}
          public void pr(long l) {w.print(l);}
          public void pr(double d) {w.print(d);}
          public void pr(String s) { w.print(s);}
          public void pl() {w.println();}
          public void close() {w.close();}
      }
      //-----------------------------------------------------------------------//
  
      //--------------------------VARIABLES------------------------------------//
      static fs sc = new fs();
      static OutputStream outputStream = System.out;
      static Printer w = new Printer(outputStream);
      static long lma = Long.MAX_VALUE, lmi = Long.MIN_VALUE;
      static int ima = Integer.MAX_VALUE, imi = Integer.MIN_VALUE;
      static long mod = 1000000007;
      //-----------------------------------------------------------------------//
  
      //--------------------------ADMIN_MODE-----------------------------------//
      private static void ADMIN_MODE() throws IOException {
          if (System.getProperty("ONLINE_JUDGE") == null) {
              w = new Printer(new FileOutputStream("output.txt"));
              sc = new fs(new FileInputStream("input.txt"));
          }
      }
      //-----------------------------------------------------------------------//
  
      //----------------------------START--------------------------------------//
      public static void main(String[] args)
              throws IOException {
  
          ADMIN_MODE();
  
          int t = sc.ni();while(t-->0)
              solve();
  
  
          w.close();
      }
  
      static void solve() throws IOException {
          int n = sc.ni();
          long k = sc.nl();
          Long[] arr = new Long[n];
          for(int i = 0; i < n; i++) arr[i] = sc.nl();
          Arrays.sort(arr);
          long sum = 0;
          for(int i = 0; i < n; i++) {
              sum += arr[i];
          }
          if(sum <= k) {
              w.p(0);
              return;
          }
  
  
          long cont = 0;
          long min = sum-k;
          for(int i = n-1; i >= 0; i--) {
              cont += arr[i];
              long psum = sum-cont;
  
  
              if(psum <= k) {
                  long extra = k-psum;
                  if(arr[0]*(n-i)<=extra) {
                      min = Math.min(min, n-i);
                      continue;
                  }
  
                  if(i == 0) {
                      long q = k/n;
                      long ans = arr[0]-q+n-1;
                      min = Math.min(min, ans);
                      continue;
                  }
                  extra += arr[0];
                  long q = extra/(n-i+1);
                  long ans = arr[0]-q+n-i;
                  min = Math.min(min, ans);
  
              } else {
                  long toRem = psum-k-arr[0];
                  long q = (long)Math.ceil(toRem/(n-i+1.0));
                  long ans = q+arr[0]+n-i;
                  min = Math.min(min, ans);
              }
          }
  
          w.p(min);
      }
  
  }