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 javax.print.attribute.standard.MediaSize;
  import java.io.BufferedReader;
  import java.io.BufferedWriter;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.OutputStreamWriter;
  import java.lang.reflect.Array;
  import java.util.*;
  import java.util.stream.Stream;
  
  public class Dummy {
  
      static BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
      static BufferedWriter out = new BufferedWriter(new OutputStreamWriter(System.out));
  
      public static void main(String[] args) throws NumberFormatException, IOException {
  
          int cases = Integer.parseInt(reader.readLine());
          int mod = 998244353;
  
          while(cases-- > 0) {
  
              String[] firstLine = reader.readLine().split(" ");
              int n = Integer.parseInt(firstLine[0]);
              long k = Long.parseLong(firstLine[1]);
  
              long[] arr = convertToLongPrimitiveArray();
              customSortLong(arr);
  
              long[] pre = new long[n];
  
              for (int i = 1; i < n; i++)
                  pre[i] = pre[i - 1] + arr[i];
  
              long ans = Long.MAX_VALUE;
  
              for (int i = n - 1; i >= 0; i--)
              {
                  long sum = pre[i];
                  long cnt = n - i;
                  long req = k - sum;
                  req = req / cnt;
  
                  for (long x = req - 5; x <= req + 5; x++)
                  {
                      if (sum + cnt * x > k) continue;
                      long curr = 0;
                      if (x <= arr[0])
                          curr += arr[0] - x;
                      curr += cnt - 1;
                      ans = Math.min(ans, curr);
                  }
              }
  
              printNumber(ans);
  
          }
  
          out.flush();
  
      }
  
      public static int ub(long[] arr, long num) {
          int start = 0;
          int end = arr.length;
          int mid = 0;
  
          while(start<end) {
              mid = start + (end-start)/2;
              if(arr[mid] < num) {
                  start = mid+1;
              }else {
                  end = mid;
              }
          }
          return start;
      }
  
      public static int[] convertToIntPrimitiveArray() throws IOException {
          String[] str = reader.readLine().split(" ");
          return Stream.of(str).mapToInt(Integer::parseInt).toArray();
      }
  
      public static Integer[] convertToIntArray(String[] str) {
          Integer[] arr = new Integer[str.length];
          for(int i=0;i<str.length;i++) {
              arr[i] = Integer.parseInt(str[i]);
          }
          return arr;
      }
  
      public static Long[] convertToLongArray(String[] str) {
          Long[] arr = new Long[str.length];
          for(int i=0;i<str.length;i++) {
              arr[i] = Long.parseLong(str[i]);
          }
          return arr;
      }
  
      public static long[] convertToLongPrimitiveArray() throws IOException {
          String[] str = reader.readLine().split(" ");
          return Stream.of(str).mapToLong(Long::parseLong).toArray();
      }
  
      public static void printYes() throws IOException {
          out.append("YES" + "\n");
      }
  
      public static void printNo() throws IOException {
          out.append("NO" + "\n");
      }
  
      public static void printNumber(long num) throws IOException {
          out.append(num + "\n");
      }
  
      public static long hcf(long a, long b) {
          if(b==0) return a;
          return hcf(b, a%b);
      }
  
      public static int findSet(int[] parent, int[] rank, int v) {
          if(v==parent[v]) {
              return v;
          }
          parent[v] = findSet(parent, rank, parent[v]);
          return parent[v];
      }
  
      public static void unionSet(int[] parent, int[] rank, int a, int b) {
  
          a = findSet(parent, rank, a);
          b = findSet(parent, rank, b);
  
          if(a == b) {
              return;
          }
  
          if(rank[a] < rank[b]) {
              int temp = a;
              a = b;
              b = temp;
          }
  
          parent[b] = a;
          if(rank[a] == rank[b]) {
              rank[a]++;
          }
  
      }
  
      public static void makeSet(int[] parent, int[] rank, int v) {
          parent[v] = v;
          rank[v] = 0;
      }
  
      public static long modularDivision(long a, long b, int mod) {
          if(a==0) return 1;
          a %= mod;
          long res = 1L;
          while(b > 0) {
              if((b&1)==1) {
                  res = (res * a)%mod;
              }
              a = (a*a)%mod;
              b >>= 1;
          }
          return res;
      }
  
      public static void customSort(int[] arr) {
          int n = arr.length;
          Random rnd = new Random();
          for(int i=0; i<n; ++i){
              int tmp = arr[i];
              int randomPos = i + rnd.nextInt(n-i);
              arr[i] = arr[randomPos];
              arr[randomPos] = tmp;
          }
          Arrays.sort(arr);
          return;
      }
  
      public static void customSortLong(long[] arr) {
          int n = arr.length;
          Random rnd = new Random();
          for(int i=0; i<n; ++i){
              long tmp = arr[i];
              int randomPos = i + rnd.nextInt(n-i);
              arr[i] = arr[randomPos];
              arr[randomPos] = tmp;
          }
          Arrays.sort(arr);
          return;
      }
  
      public static long[] factorial(int n, int mod) {
          long[] fact = new long[n+1];
          fact[0] = 1;
          for(int i=1;i<fact.length;i++) {
              fact[i] = (i*fact[i-1] + mod)%mod;
          }
          return fact;
      }
  
      public static List<Integer> primeNumbers(int num) {
          boolean[] arr = new boolean[num+1];
          List<Integer> primes = new ArrayList<>();
  
          for(int i=2;i*i<=num;i++) {
              if(!arr[i]) {
                  for(int j=i;j*i<=num;j++) {
                      arr[j*i] = true;
                  }
              }
          }
  
          for(int i=2;i<=num;i++) {
              if(!arr[i]) {
                  primes.add(i);
              }
          }
          return primes;
      }
  
  
  }