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: /*
   * akshaygupta26
   */
  import java.io.*;
  import java.util.*;
  public class C
  {
  	
  	static long mod =(long)(1e9+7);
      public static void main(String[] args) 
  	{ 
  		FastReader sc=new FastReader(); 
  		StringBuilder ans=new StringBuilder();
  		int test=sc.nextInt();
  		while(test-->0)
  		{
  			int n=sc.nextInt();
  			long k=sc.nextLong();
  			long arr[]=new long[n];
  			for(int i=0;i<n;i++) {
  				arr[i]=sc.nextLong();
  			}
  			
  			ruffleSort(arr);
  			long pre[]=new long[n];
  			pre[0] = arr[0];
  			for(int i=1;i<n;i++) {
  				pre[i]=pre[i-1]+arr[i];
  			}
  			
  			long minm=Long.MAX_VALUE;
  			
  			if(pre[n-1] <= k) {
  				ans.append(0+"\n");
  				continue;
  			}
  			
  			//Handling zero
  			minm=((pre[n-1])-k);
  			
  			
  			for(int elementsReplacedFromLast=1;elementsReplacedFromLast<=n-1;elementsReplacedFromLast++) {
  				long sum = pre[n-1-(elementsReplacedFromLast)] - pre[0];
  
  				long steps =0;
  				if(sum>k) {
  					long neg_needed = sum-k;
  					long per_element_needed = (neg_needed)/(elementsReplacedFromLast+1);
  					if((elementsReplacedFromLast+1) * per_element_needed != neg_needed) per_element_needed++;
  					steps = elementsReplacedFromLast;
  					if(arr[0]>(-1l*per_element_needed)) steps+=(arr[0]+per_element_needed);
  					
  				}
  				else if(sum == k) {
  					steps = elementsReplacedFromLast + (pre[0]>0?pre[0]:0);
  				}
  				else {
  					long sum_allowed=k-sum;
  					long per_element_allowance = sum_allowed/(elementsReplacedFromLast+1);
  					steps = elementsReplacedFromLast;
  					if(arr[0]>per_element_allowance) steps+=(arr[0]-per_element_allowance);
  				}
  				
  				minm=Math.min(minm, steps);
  			}
  			
  			ans.append(minm+"\n");
  		}
  		
  	    System.out.print(ans);
  	} 
      
      static long ceil(double a,double b) {
      	return (long)Math.ceil(a/b);
      }
      static long add(long a,long b) {
      	return (a+b)%mod;
      }
      static long mult(long a,long b) {
      	return (a*b)%mod;
      }
   
      static long _gcd(long a,long b) {
      	if(b == 0) return a;
      	return _gcd(b,a%b);
      }
      
      static final Random random=new Random();
      
  	static void ruffleSort(int[] a) {
  		int n=a.length;//shuffle, then sort 
  		for (int i=0; i<n; i++) {
  			int oi=random.nextInt(n), temp=a[oi];
  			a[oi]=a[i]; a[i]=temp;
  		}
  		Arrays.sort(a);
  	}
  	
  	static void ruffleSort(long[] a) {
  		int n=a.length;//shuffle, then sort 
  		for (int i=0; i<n; i++) {
  			int oi=random.nextInt(n);
  			long temp=a[oi];
  			a[oi]=a[i]; a[i]=temp;
  		}
  		Arrays.sort(a);
  	}
  	
  	static class FastReader 
  	{ 
  		BufferedReader br; 
  		StringTokenizer st; 
  
  		public FastReader() 
  		{ 
  			br = new BufferedReader(new
  					InputStreamReader(System.in)); 
  		} 
  
  		String next() 
  		{ 
  			while (st == null || !st.hasMoreElements()) 
  			{ 
  				try
  				{ 
  					st = new StringTokenizer(br.readLine()); 
  				} 
  				catch (IOException e) 
  				{ 
  					e.printStackTrace(); 
  				} 
  			} 
  			return st.nextToken(); 
  		} 
  
  		int nextInt() 
  		{ 
  			return Integer.parseInt(next()); 
  		} 
  
  		long nextLong() 
  		{ 
  			return Long.parseLong(next()); 
  		} 
  
  		double nextDouble() 
  		{ 
  			return Double.parseDouble(next()); 
  		} 
  
  		String nextLine() 
  		{ 
  			String str = ""; 
  			try
  			{ 
  				str = br.readLine(); 
  			} 
  			catch (IOException e) 
  			{ 
  				e.printStackTrace(); 
  			} 
  			return str; 
  		} 
  	} 
  
  
  } 
  