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.IOException;
  
      import java.io.IOException;
      import java.io.InputStream;
      import java.io.PrintWriter;
      import java.util.*;
  
      public class SetorDecrease {
          static InputReader inputReader=new InputReader(System.in);
          static void solve()
          {
              int n=inputReader.nextInt();
              long k=inputReader.nextLong();
              long sum=0;
              long arr[]=new long[n];
              for (int i=0;i<n;i++)
              {
                  arr[i]=inputReader.nextLong();
              }
              SortDec(arr);
              for (int i=0;i<n-1;i++)
              {
                  sum+=arr[i];
              }
              long ans=Long.MAX_VALUE;
              for (int i=0;i<n;i++)
              {
                 long remval=k-sum;
                 long val=fdiv(remval,i+1);
                 ans=Math.min(ans,i+Math.max(arr[n-1]-val,0));
                 sum-=arr[i];
              }
              out.println(ans);
          }
          static void SortDec(long arr[])
          {
              List<Long>list=new ArrayList<>();
              for(long ele:arr)
              {
                  list.add(ele);
              }
              Collections.sort(list,Collections.reverseOrder());
              int n=arr.length;
              for (int i=0;i<n;i++)
              {
                  arr[i]=list.get(i);
  
              }
  
          }
         static long fdiv(long X, long Y) {
              if (X >= 0) {
                  return X / Y;
              } else {
                  return (X-Y+1) / Y;
              }
          }
          static PrintWriter out=new PrintWriter((System.out));
          public static void main(String args[])throws IOException
          {
              int t=inputReader.nextInt();
              while (t-->0) {
                  solve();
              }
                  out.close();
          }
          static class InputReader {
  
              private InputStream stream;
              private byte[] buf = new byte[8192];
              private int curChar, snumChars;
              private SpaceCharFilter filter;
  
              public InputReader(InputStream stream) {
                  this.stream = stream;
              }
  
              public int snext() {
                  if (snumChars == -1)
                      throw new InputMismatchException();
                  if (curChar >= snumChars) {
                      curChar = 0;
                      try {
                          snumChars = stream.read(buf);
                      } catch (IOException e) {
                          throw new InputMismatchException();
                      }
                      if (snumChars <= 0)
                          return -1;
                  }
                  return buf[curChar++];
              }
  
              public int nextInt() {
                  int c = snext();
                  while (isSpaceChar(c))
                      c = snext();
                  int sgn = 1;
                  if (c == '-') {
                      sgn = -1;
                      c = snext();
                  }
                  int res = 0;
                  do {
                      if (c < '0' || c > '9')
                          throw new InputMismatchException();
                      res *= 10;
                      res += c - '0';
                      c = snext();
                  } while (!isSpaceChar(c));
                  return res * sgn;
              }
  
              public long nextLong() {
                  int c = snext();
                  while (isSpaceChar(c))
                      c = snext();
                  int sgn = 1;
                  if (c == '-') {
                      sgn = -1;
                      c = snext();
                  }
                  long res = 0;
                  do {
                      if (c < '0' || c > '9')
                          throw new InputMismatchException();
                      res *= 10;
                      res += c - '0';
                      c = snext();
                  } while (!isSpaceChar(c));
                  return res * sgn;
              }
  
              public int[] nextIntArray(int n) {
                  int a[] = new int[n];
                  for (int i = 0; i < n; i++)
                      a[i] = nextInt();
                  return a;
              }
  
              public String readString() {
                  int c = snext();
                  while (isSpaceChar(c))
                      c = snext();
                  StringBuilder res = new StringBuilder();
                  do {
                      res.appendCodePoint(c);
                      c = snext();
                  } while (!isSpaceChar(c));
                  return res.toString();
              }
  
              public boolean isSpaceChar(int c) {
                  if (filter != null)
                      return filter.isSpaceChar(c);
                  return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
              }
  
              public interface SpaceCharFilter {
                  public boolean isSpaceChar(int ch);
              }
          }
      }
  