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.*;
  import java.text.*;
  import java.math.*;
  import java.util.regex.*;
  
  public class JaiShreeRam{
  	static Scanner in=new Scanner();
  	static long mod = 1000000007;
  	static ArrayList<ArrayList<Integer>> adj;
  	static int seive[]=new int[1000001];
  	public static void main(String[] args) throws Exception{
  		int z=in.readInt();
  		while(z-->0) {
  			solve();
  		}
  	}
  	static void solve() {
  		int n=in.readInt();
  		long k=in.readLong();
  		Long l[]=nLa(n);
  		long sum=0;
  		for(long i:l){
  			sum+=i;
  		}
  		if(sum<=k) {
  			System.out.println(0);
  		}
  		else if(sum==k+1) {
  			System.out.println(1);
  		}
  		else {
  			Arrays.sort(l);
  			long dif=sum-k;
  			long ans=dif;
  			sum=0;
  			for(int i=n-1;i>0;i--) {
  				sum+=l[i];
  				long x=(long)Math.ceil((double)(dif+(n-i)*l[0]-sum)/(double)(n-i+1));
  				x=Math.max(0, x);
  				ans=Math.min(ans, x+n-i);
  				//System.out.println(ans+" "+x);
  			}
  			System.out.println(ans);
  		}
  	}
  	static void seive() {
  		Arrays.fill(seive, 1);
  		seive[0]=0;
  		seive[1]=0;
  		for(int i=2;i*i<1000001;i++) {
  			if(seive[i]==1) {
  				for(int j=i*i;j<1000001;j+=i) {
  					if(seive[j]==1) {
  						seive[j]=0;
  					}
  				}
  			}
  		}
  	}
  	static int[] nia(int n){
  		int[] arr= new int[n];
  		int i=0;
  		while(i<n){
  			arr[i++]=in.readInt();
  		}
  		return arr;
  	}
  	static long[] nla(int n){
  		long[] arr= new long[n];
  		int i=0;
  		while(i<n){
  			arr[i++]=in.readLong();
  		}
  		return arr;
  	}
  	static int[] nia1(int n){
  		int[] arr= new int[n+1];
  		int i=1;
  		while(i<=n){
  			arr[i++]=in.readInt();
  		}
  		return arr;
  	}
  	static Integer[] nIa(int n){
  		Integer[] arr= new Integer[n];
  		int i=0;
  		while(i<n){
  			arr[i++]=in.readInt();
  		}
  		return arr;
  	}
  	static Long[] nLa(int n){
  		Long[] arr= new Long[n];
  		int i=0;
  		while(i<n){
  			arr[i++]=in.readLong();
  		}
  		return arr;
  	}
  	static long gcd(long a, long b) {
  		if (b==0) return a;
  		return gcd(b, a%b);
  	}
  	static class Scanner{
  		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
  		StringTokenizer st=new StringTokenizer("");
  		String readString() {
  			while (!st.hasMoreTokens())
  				try {
  					st=new StringTokenizer(br.readLine());
  				} catch (IOException e) {
  					e.printStackTrace();
  				}
  			return st.nextToken();
  		}
  		double readDouble() {
  			return Double.parseDouble(readString());
  		}
  		int readInt() {
  			return Integer.parseInt(readString());
  		}
  		long readLong() {
  			return Long.parseLong(readString());
  		}
  	}
  }