In a strategic computer game "Settlers II" one has to build defense structures to expand and protect the territory. Let's take one of these buildings. At the moment the defense structure accommodates exactly n soldiers. Within this task we can assume that the number of soldiers in the defense structure won't either increase or decrease.

Every soldier has a rank — some natural number from 1 to k. 1 stands for a private and k stands for a general. The higher the rank of the soldier is, the better he fights. Therefore, the player profits from having the soldiers of the highest possible rank.

To increase the ranks of soldiers they need to train. But the soldiers won't train for free, and each training session requires one golden coin. On each training session all the n soldiers are present.

At the end of each training session the soldiers' ranks increase as follows. First all the soldiers are divided into groups with the same rank, so that the least possible number of groups is formed. Then, within each of the groups where the soldiers below the rank k are present, exactly one soldier increases his rank by one.

You know the ranks of all n soldiers at the moment. Determine the number of golden coins that are needed to increase the ranks of all the soldiers to the rank k.

Input

The first line contains two integers n and k (1 ≤ n, k ≤ 100). They represent the number of soldiers and the number of different ranks correspondingly. The second line contains n numbers in the non-decreasing order. The i-th of them, ai, represents the rank of the i-th soldier in the defense building (1 ≤ i ≤ n, 1 ≤ ai ≤ k).

Output

Print a single integer — the number of golden coins needed to raise all the soldiers to the maximal rank.

Examples

Input

4 4
1 2 2 3


Output

4

Input

4 3
1 1 1 1


Output

5

Note

In the first example the ranks will be raised in the following manner:

1 2 2 3 →  2 2 3 4 →  2 3 4 4 →  3 4 4 4 →  4 4 4 4

Thus totals to 4 training sessions that require 4 golden coins.
/*
    Aman Agarwal
    algo.java
*/

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

public class B63
{
    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;
            }
    }


    static FastReader sc = new FastReader();
    static PrintWriter out = new PrintWriter(System.out);
    static int ni()throws IOException{return sc.nextInt();}
    static long nl()throws IOException{return sc.nextLong();}
    static int[][] nai2(int n,int m)throws IOException{int a[][] = new int[n][m];for(int i=0;i<n;i++)for(int j=0;j<m;j++)a[i][j] = ni();return a;}
    static int[] nai(int N,int start)throws IOException{int[]A=new int[N+start];for(int i=start;i!=(N+start);i++){A[i]=ni();}return A;}
    static Integer[] naI(int N,int start)throws IOException{Integer[]A=new Integer[N+start];for(int i=start;i!=(N+start);i++){A[i]=ni();}return A;}
    static long[] nal(int N)throws IOException{long[]A=new long[N];for(int i=0;i!=N;i++){A[i]=nl();}return A;}
    static void print(int arr[]){for(int i=0;i<arr.length;i++)out.print(arr[i]+" ");out.println();}
    static void print(long arr[]){for(int i=0;i<arr.length;i++)out.print(arr[i]+" ");out.println();}
    static long gcd(long a, long b)throws IOException{return (b==0)?a:gcd(b,a%b);}
    static int gcd(int a, int b)throws IOException{return (b==0)?a:gcd(b,a%b);}
    static int bit(long n)throws IOException{return (n==0)?0:(1+bit(n&(n-1)));} // return the number of set bits.
    static boolean isPrime(int number){if(number==1) return false;if (number == 2 || number == 3){return true;}if (number % 2 == 0) {return false;}int sqrt = (int) Math.sqrt(number) + 1;for(int i = 3; i < sqrt; i += 2){if (number % i == 0){return false;}}return true;}
    static boolean isPrime(long number){if(number==1) return false;if (number == 2 || number == 3){return true;}if (number % 2 == 0) {return false;}long sqrt = (long) Math.sqrt(number) + 1;for(int i = 3; i < sqrt; i += 2){if (number % i == 0){return false;}}return true;}
    static int power(int n,int p){if(p==0)return 1;int a = power(n,p/2);a = a*a;int b = p & 1;if(b!=0){a =  n*a;}return a;}
    static long power(long n,long p){if(p==0)return 1;long a = power(n,p/2);a = a*a;long b = p & 1;if(b!=0){a =  n*a;}return a;}
    static void reverse(int[] a) {int b;for (int i = 0, j = a.length - 1; i < j; i++, j--) {b = a[i];a[i] = a[j];a[j] = b;}}
    static void reverse(long[] a) {long b;for (int i = 0, j = a.length - 1; i < j; i++, j--) {b = a[i];a[i] = a[j];a[j] = b;}}
    static void swap(int a[],int i,int j){a[i] = a[i] ^ a[j];a[j] = a[j] ^ a[i];a[i] = a[i] ^ a[j];}
    static void swap(long a[],int i,int j){a[i] = a[i] ^ a[j];a[j] = a[j] ^ a[i];a[i] = a[i] ^ a[j];}
    static int count(int n){int c=0;while(n>0){c++;n = n/10;}return c;}
    static int[] prefix_sum(int a[],int n){int s[] = new int[n];s[0] = a[0];for(int i=1;i<n;i++){s[i] = a[i]+s[i-1];}return s;}
    static long[] prefix_sum_int(int a[],int n){long s[] = new long[n];s[0] = (long)a[0];for(int i=1;i<n;i++){s[i] = ((long)a[i])+s[i-1];}return s;}
    static long[] prefix_sum_Integer(Integer a[],int n){long s[] = new long[n];s[0] = (long)a[0];for(int i=1;i<n;i++){s[i] = ((long)a[i])+s[i-1];}return s;}
    static long[] prefix_sum_long(long a[],int n){long s[] = new long[n];s[0] = a[0];for(int i=1;i<n;i++){s[i] = a[i]+s[i-1];}return s;}
    static boolean isPerfectSquare(double x){double sr = Math.sqrt(x);return ((sr - Math.floor(sr)) == 0);}
    static ArrayList<Integer> sieve(int n) {int k=0; boolean prime[] = new boolean[n+1];ArrayList<Integer> p_arr = new ArrayList<>();for(int i=0;i<n;i++) prime[i] = true;for(int p = 2; p*p <=n; p++){ k=p;if(prime[p] == true) { p_arr.add(p);for(int i = p*2; i <= n; i += p) prime[i] = false; } }for(int i = k+1;i<=n;i++){if(prime[i]==true)p_arr.add(i);}return p_arr;} 
    static boolean[] seive_check(int n) {boolean prime[] = new boolean[n+1];for(int i=0;i<n;i++) prime[i] = true;for(int p = 2; p*p <=n; p++){ if(prime[p] == true) { for(int i = p*2; i <= n; i += p) prime[i] = false; } }prime[1]=false;return prime;} 
    static int get_bits(int n){int p=0;while(n>0){p++;n = n>>1;}return p;}
    static int get_bits(long n){int p=0;while(n>0){p++;n = n>>1;}return p;}
    static int get_2_power(int n){if((n & (n-1))==0)return get_bits(n)-1;return -1;}
    static int get_2_power(long n){if((n & (n-1))==0)return get_bits(n)-1;return -1;}
    static void close(){out.flush();}

    /*-------------------------Main Code Starts(algo.java)----------------------------------*/    

    public static void main(String[] args) throws IOException 
    {
        int test = 1;
        //test = sc.nextInt();
        while(test-- > 0)
        {
            int n = ni();
            int k = ni();
            int arr[] = new int[n+1];
            for(int i=0;i<n;i++)
                arr[i] = ni();
            //arr[n] = k;
            int ans=0;
            while(arr[0]!=k)
            {
                for(int i=0;i<n;i++)
                    if(arr[i]!=arr[i+1])
                        arr[i]++;
                ans++;
            }
            out.println(ans);
        }
        close();
    }
}
