The only difference between easy and hard versions is the constraints.

Polycarp has to write a coursework. The coursework consists of m pages.

Polycarp also has n cups of coffee. The coffee in the i-th cup has a_i caffeine in it. Polycarp can drink some cups of coffee (each one no more than once). He can drink cups in any order. Polycarp drinks each cup instantly and completely (i.e. he cannot split any cup into several days).

Surely, courseworks are not usually being written in a single day (in a perfect world of Berland, at least). Some of them require multiple days of hard work.

Let's consider some day of Polycarp's work. Consider Polycarp drinks k cups of coffee during this day and caffeine dosages of cups Polycarp drink during this day are a_{i_1}, a_{i_2}, ..., a_{i_k}. Then the first cup he drinks gives him energy to write a_{i_1} pages of coursework, the second cup gives him energy to write max(0, a_{i_2} - 1) pages, the third cup gives him energy to write max(0, a_{i_3} - 2) pages, ..., the k-th cup gives him energy to write max(0, a_{i_k} - k + 1) pages.

If Polycarp doesn't drink coffee during some day, he cannot write coursework at all that day.

Polycarp has to finish his coursework as soon as possible (spend the minimum number of days to do it). Your task is to find out this number of days or say that it is impossible.

Input

The first line of the input contains two integers n and m (1 ≤ n ≤ 100, 1 ≤ m ≤ 10^4) — the number of cups of coffee and the number of pages in the coursework.

The second line of the input contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 100), where a_i is the caffeine dosage of coffee in the i-th cup.

Output

If it is impossible to write the coursework, print -1. Otherwise print the minimum number of days Polycarp needs to do it.

Examples

Input


5 8
2 3 1 1 2


Output


4


Input


7 10
1 3 4 2 1 4 2


Output


2


Input


5 15
5 5 5 5 5


Output


1


Input


5 16
5 5 5 5 5


Output


2


Input


5 26
5 5 5 5 5


Output


-1

Note

In the first example Polycarp can drink fourth cup during first day (and write 1 page), first and second cups during second day (and write 2 + (3 - 1) = 4 pages), fifth cup during the third day (and write 2 pages) and third cup during the fourth day (and write 1 page) so the answer is 4. It is obvious that there is no way to write the coursework in three or less days in this test.

In the second example Polycarp can drink third, fourth and second cups during first day (and write 4 + (2 - 1) + (3 - 2) = 6 pages) and sixth cup during second day (and write 4 pages) so the answer is 2. It is obvious that Polycarp cannot write the whole coursework in one day in this test.

In the third example Polycarp can drink all cups of coffee during first day and write 5 + (5 - 1) + (5 - 2) + (5 - 3) + (5 - 4) = 15 pages of coursework.

In the fourth example Polycarp cannot drink all cups during first day and should drink one of them during the second day. So during first day he will write 5 + (5 - 1) + (5 - 2) + (5 - 3) = 14 pages of coursework and during second day he will write 5 pages of coursework. This is enough to complete it.

In the fifth example Polycarp cannot write the whole coursework at all, even if he will drink one cup of coffee during each day, so the answer is -1.
//package sept;

import java.io.*;
import java.util.*;



public class TimePass implements Runnable {
    InputStream is;
    PrintWriter out;
    String INPUT = "";
    //boolean debug=false;
    boolean debug=true;
    static long mod=998244353;
    static long mod2=1000000007;
    
    void solve() throws IOException
	{
	    int n=ni(),m=ni();
	    long[] a=new long[n];
	    for(int i=0;i<n;i++)a[i]=nl();
	    a=radixSort(a);
	    long low=0,high=n+1;
	    long sum=0;
	    while(low<high-1)
	    {
	        long mid=(low+high)/2;
	        long cnt1=0,cnt2=0;
	        sum=0;
	        for(int i=n-1;i>=0;i--)
	        {
	            sum+=Math.max(0,a[i]-cnt1);
	            cnt2++;
	            if(cnt2==mid)
	            {
	                cnt2=0;
	                cnt1++;
	            }
	        }
	        if(sum>=m)
	        {
	            high=mid;
	        }
	        else low=mid;
	    }
	    if(high==n+1)out.println(-1);
	    else out.println(high);
	}
	
	static int comp(char[] a,int st,int end)
	{
	    int len=end-st+1;
	    if(len==3)return 2;
	    if(len==2)return -1;
	    int mid=(st+end)/2;
	    if(len%2!=0)mid--;
	    int ch2=1;
	    for(int i=0;i<len;i++)
	    {
	        if(a[st+i]!=a[len-1])
	        {
	            ch2=0;
	            break;
	        }
	    }
	    if(ch2==1)
	    {
	        return -1;
	    }
	    int ch=1;
	    for(int i=0;i<len/4;i++)
	    {
	        if(a[i+st]!=a[mid-i])
	        {
	            ch=0;
	            break;
	        }
	    }
	    if(ch==1)return 2*comp(a,st,mid);
	    if(len%2==0)return 1;
	    return 2;
	}
    
    static int[] xor;
    
    static void dfs(int u,int[] a,int[][] g,int[] vis)
    {
    	xor[u]=a[u];
    	
    	vis[u]=1;
    	for(int v:g[u])
    	{
    		if(vis[v]==0)
    		{
    			dfs(v,a,g,vis);
    			xor[u]=xor[u]^xor[v];
    		}
    	}
    }

	static int[][] packD(int n,int[] from,int[] to)
	{
		int[][] g=new int[n][];
		int[] p=new int[n];
		for(int f:from)
		{
			p[f]++;
		}
		int m=from.length;
		for(int i=0;i<n;i++)
		{
			g[i]=new int[p[i]];
		}
		for(int i=0;i<m;i++)
		{
			g[from[i]][--p[from[i]]]=to[i];
		}
		return g;
	}
	    
    static class Pair
    {
        int a,b;
        public Pair(int a,int b)
        {
            this.a=a;
            this.b=b;
            //this.ind=ind;
        }
    }
    
    static long lcm(int a,int b)
    {
        long val=a;
        val*=b;
        return (val/gcd(a,b));
    }
    
    static long gcd(long a,long b)
    {
        if(a==0)return b;
        return gcd(b%a,a);
    }
    
    static int pow(int a, int b, int p)
    {
        long ans = 1, base = a;
        while (b!=0)
        {
            if ((b & 1)!=0)
            {
                ans *= base;
                ans%= p;
            }
            base *= base;
            base%= p;
            b >>= 1;
        }
        return (int)ans;
    }

    static int inv(int x, int p)
    {
        return pow(x, p - 2, p);
    }
    
    public static long[] radixSort(long[] f){ return radixSort(f, f.length); }
	public static long[] radixSort(long[] f, int n)
	{
		long[] to = new long[n];
		{
			int[] b = new int[65537];
			for(int i = 0;i < n;i++)b[1+(int)(f[i]&0xffff)]++;
			for(int i = 1;i <= 65536;i++)b[i]+=b[i-1];
			for(int i = 0;i < n;i++)to[b[(int)(f[i]&0xffff)]++] = f[i];
			long[] d = f; f = to;to = d;
		}
		{
			int[] b = new int[65537];
			for(int i = 0;i < n;i++)b[1+(int)(f[i]>>>16&0xffff)]++;
			for(int i = 1;i <= 65536;i++)b[i]+=b[i-1];
			for(int i = 0;i < n;i++)to[b[(int)(f[i]>>>16&0xffff)]++] = f[i];
			long[] d = f; f = to;to = d;
		}
		{
			int[] b = new int[65537];
			for(int i = 0;i < n;i++)b[1+(int)(f[i]>>>32&0xffff)]++;
			for(int i = 1;i <= 65536;i++)b[i]+=b[i-1];
			for(int i = 0;i < n;i++)to[b[(int)(f[i]>>>32&0xffff)]++] = f[i];
			long[] d = f; f = to;to = d;
		}
		{
			int[] b = new int[65537];
			for(int i = 0;i < n;i++)b[1+(int)(f[i]>>>48&0xffff)]++;
			for(int i = 1;i <= 65536;i++)b[i]+=b[i-1];
			for(int i = 0;i < n;i++)to[b[(int)(f[i]>>>48&0xffff)]++] = f[i];
			long[] d = f; f = to;to = d;
		}
		return f;
	}

    
    public void run()
    {
        if(debug)oj=true;
        is = oj ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);
        
        long s = System.currentTimeMillis();
        try {
			solve();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
        out.flush();
        tr(System.currentTimeMillis()-s+"ms");
    }
    
    public static void main(String[] args) throws Exception {new Thread(null,new TimePass(),"Main",1<<26).start();}
    
    private byte[] inbuf = new byte[1024];
    public int lenbuf = 0, ptrbuf = 0;
    
    private int readByte()
    {
        if(lenbuf == -1)throw new InputMismatchException();
        if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        }
        return inbuf[ptrbuf++];
    }
    
    private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
    private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
    
    private double nd() { return Double.parseDouble(ns()); }
    private char nc() { return (char)skip(); }
    
    private String ns()
    {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    
    private char[] ns(int n)
    {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while(p < n && !(isSpaceChar(b))){
            buf[p++] = (char)b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    }
    
    private char[][] nm(int n, int m)
    {
        char[][] map = new char[n][];
        for(int i = 0;i < n;i++)map[i] = ns(m);
        return map;
    }
    
    private int[] na(int n)
    {
        int[] a = new int[n];
        for(int i = 0;i < n;i++)a[i] = ni();
        return a;
    }
    
    private int ni()
    {
        int num = 0, b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }
        
        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }
    
    private long nl()
    {
        long num = 0;
        int b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }
        
        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }
    
    private boolean oj = System.getProperty("ONLINE_JUDGE") != null;
    private void tr(Object... o) { if(!oj)System.out.println(Arrays.deepToString(o)); }
}