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.util.*;
  import java.io.*;
  
  public class C {
  
      static FastScanner fs = new FastScanner();
      static Scanner scn = new Scanner(System.in);
      static PrintWriter pw = new PrintWriter(System.out);
      static StringBuilder sb = new StringBuilder("");
      static int K = 18;
      static int N = 200000;
      static long INF = (long) 10e18;
      static int[] a, pre;
      static int t, n, s, max;
      static Pair[] pairs;
  
      public static void main(String[] args) {
          int t = fs.nextInt();
          for (int tt = 0; tt < t; tt++) {
              int n = fs.nextInt();
              long k = fs.nextLong();
              long[] a = new long[n];
              for (int i = 0; i < n; i++) a[i] = fs.nextInt();
              sort(a);
              long[] b = new long[n+1];
              for (int i = 0; i < n; i++) b[i+1] = b[i] + a[i];
              long ans = (long) 10e18;
              for (int i = 0; i < n; i++) {
                  long sum = b[n-i] + a[0] * i;
                  long cur = i;
                  if (sum > k) {
                      long diff = sum - k;
                      cur += (diff + i) / (i + 1);
                  }
                  ans = Math.min(ans, cur);
              }
              sb.append(ans + "\n");
          }
          pw.print(sb.toString());
          pw.close();
      }
  
      static int gcd(int a, int b) {
          if (b == 0)
              return a;
          return gcd(b, a % b);
      }
  
      static boolean ok(long x) {
  
          return false;
      }
  
      static void swap(ArrayList<Integer> x, ArrayList<Integer> y) {
          ArrayList<Integer> temp = new ArrayList<>();
          for (int i = 0; i < x.size(); i++)
              temp.add(x.get(i));
          for (int i = 0; i < y.size(); i++)
              x.add(y.get(i));
          for (int i = 0; i < temp.size(); i++)
              y.add(temp.get(i));
      }
  
      static void sort(long[] a) {
          ArrayList<Long> al = new ArrayList<>();
          for (long i : a)
              al.add(i);
          Collections.sort(al);
          for (int i = 0; i < a.length; i++)
              a[i] = al.get(i);
      }
  
      static class Pair implements Comparable<Pair> {
          int first = 0;
          int second = 0;
  
          Pair(int first, int second) {
              this.first = first;
              this.second = second;
          }
  
          public int compareTo(Pair o) {
              return Integer.compare(first, o.first);
          }
      }
  
      static class FastScanner {
          BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
          StringTokenizer st = new StringTokenizer("");
  
          String next() {
              while (!st.hasMoreTokens())
                  try {
                      st = new StringTokenizer(br.readLine());
                  } catch (IOException e) {
                  }
              return st.nextToken();
          }
  
          int nextInt() {
              return Integer.parseInt(next());
          }
  
          long nextLong() {
              return Long.parseLong(next());
          }
  
          double nextDouble() {
              return Double.parseDouble(next());
          }
  
          int[] readArray(int n) {
              int[] a = new int[n];
              for (int i = 0; i < n; i++) {
                  a[i] = nextInt();
              }
              return a;
          }
      }
  }