You and your friend are participating in a TV show "Run For Your Prize".

At the start of the show n prizes are located on a straight line. i-th prize is located at position ai. Positions of all prizes are distinct. You start at position 1, your friend — at position 106 (and there is no prize in any of these two positions). You have to work as a team and collect all prizes in minimum possible time, in any order.

You know that it takes exactly 1 second to move from position x to position x + 1 or x - 1, both for you and your friend. You also have trained enough to instantly pick up any prize, if its position is equal to your current position (and the same is true for your friend). Carrying prizes does not affect your speed (or your friend's speed) at all.

Now you may discuss your strategy with your friend and decide who will pick up each prize. Remember that every prize must be picked up, either by you or by your friend.

What is the minimum number of seconds it will take to pick up all the prizes?

Input

The first line contains one integer n (1 ≤ n ≤ 105) — the number of prizes.

The second line contains n integers a1, a2, ..., an (2 ≤ ai ≤ 106 - 1) — the positions of the prizes. No two prizes are located at the same position. Positions are given in ascending order.

Output

Print one integer — the minimum number of seconds it will take to collect all prizes.

Examples

Input

3
2 3 9


Output

8


Input

2
2 999995


Output

5

Note

In the first example you take all the prizes: take the first at 1, the second at 2 and the third at 8.

In the second example you take the first prize in 1 second and your friend takes the other in 5 seconds, you do this simultaneously, so the total time is 5.
import java.util.*;
import java.math.*;
import java.io.*; 
 public class A{

static FastReader scan=new FastReader();
 public static PrintWriter out = new PrintWriter (new BufferedOutputStream(System.out));
  static LinkedList<Edge>edges[];
  static boolean stdin = true;
    static String filein = "input";
    static String fileout = "output";
static int dx[] = { -1, 0, 1, 0 };
static int dy[] = { 0, 1, 0, -1 };
int dx_8[]={1,1,1,0,0,-1,-1,-1};
int dy_8[]={-1,0,1,-1,1,-1,0,1};
static char sts[]={'U','R','D','L'};
static boolean prime[];
static long LCM(long a,long b){
    return (Math.abs(a*b))/gcd(a,b);
   }
   static long gcd(long a, long b) {
    if(a!=0&&b!=0)
        while((a%=b)!=0&&(b%=a)!=0);
    return a^b;
}
static int countSetBits(int n) 
    { 
        int count = 0; 
        while (n > 0) { 
            count += n & 1; 
            n >>= 1; 
        } 
        return count; 
    } 
 static void sieve(long n) 
    { 
        
        prime = new boolean[(int)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*p; i <= n; i += p) 
                    prime[i] = false; 
            } 
        } 
    }  
  
 
 
           static boolean isprime(long x)
           {
            for(long i=2;i*i<=x;i++)
                if(x%i==0)
                    return false;
                return true;
           }
           static int perm=0,FOR=0;
           
     

static boolean flag=false;
static int len=100000000;

static ArrayList<Pair>inters=new ArrayList<Pair>();





static StringBuilder sb;
static void swap(int i,int j,StringBuilder st)
{
    char tmp=st.charAt(i);
    st.setCharAt(i,st.charAt(j));
    st.setCharAt(j,tmp);
}


 private static int next(int[] arr, int target)  
    {  
        int start = 0, end = arr.length - 1;  
    
        int ans = -1;  
        while (start <= end) {  
            int mid = (start + end) / 2;  
    
            // Move to right side if target is  
            // greater.  
            if(arr[mid]==target)
                return mid;
            if (arr[mid] <target) {  
                start = mid + 1;  
            }  
    
            // Move left side.  
            else {  
                ans = mid;  
                end = mid - 1;  
            }  
        }  
        return ans;  
    }  
//static boolean vis[][];
    static long solve(int h,long n,int cur)
    {
        if(h==0)
            return 0;
        long half=1L<<(h-1);
        if(n<=half)
        {
            if((cur^1)==0)
                return 1+solve(h-1,n,0);
            else 
                return 2*half+solve(h-1,n,0);
        }
        else 
        {
              if((cur^1)==0)
             return 2*half+solve(h-1,n-half,1);
            else 
                return 1+solve(h-1,n-half,1);
        }
    }
static int dist[][];
public static String removeLeadingZeroes(String str) {
      String strPattern = "^0+(?!$)";
      str = str.replaceAll(strPattern, "");
      return str;
   }

    static String gcd(String str1, String str2)
    {
        // If str1 length is less than
        // that of str2 then recur
        // with gcd(str2, str1)
        if (str1.length() < str2.length()) {
            return gcd(str2, str1);
        }
 
        // If str1 is not the
        // concatenation of str2
        else if (!str1.startsWith(str2)) {
            return "";
        }
 
        else if (str2.isEmpty()) {
 
            // GCD string is found
            return str1;
        }
        else {
 
            // Cut off the common prefix
            // part of str1 & then recur
            return gcd(str1.substring(str2.length()),
                       str2);
        }
    }
   static ArrayList<Long>luckies=new ArrayList<Long>();
static void d(long x)
{
    if(x>=(long)1e10)
        return;
    luckies.add(x);
    d(x*10+4);
    d(x*10+7);
}
static boolean isSubSequence(String str1,  
                    String str2, int m, int n) 
    { 
        int j = 0; 
          
        // Traverse str2 and str1, and compare  
        // current character of str2 with first 
        // unmatched char of str1, if matched  
        // then move ahead in str1 
        for (int i = 0; i < n && j < m; i++) 
            if (str1.charAt(j) == str2.charAt(i)) 
                j++; 
  
        // If all characters of str1 were found 
        // in str2 
        return (j == m);  
    }
    
  
static long find(int x,int y)
{
    if(x>y)
        return 1;
    long l=find(x+1,y);
    out.println(l);
     //ans=pow(arr[x],l);
    return 0;
}
static int sum(int x)
{
    int res=0;
    while(x>0)
    {
        res+=(x%10);
        x/=10;
    }
    return res;
}


static boolean vis[]=new boolean[101];
static int n,m;
static ArrayList<Pair>res=new ArrayList<Pair>();
static String arr[];
static void swap(int i,int j)
{
    String tmp=arr[i];
    arr[i]=arr[j];
    arr[j]=tmp;
}
static void sort()
{
    int n = arr.length; 
        for (int i = 0; i < n-1; i++) 
            for (int j = 0; j < n-i-1; j++) 
                if (arr[j].length() >arr[j+1].length()) 
                {  
                    swap(j+1,j);
                } 

}
public static class comp1 implements Comparator<Pair>{  
public int compare(Pair o1,Pair o2){  
return (o2.x-o2.y)-(o1.x-o1.y);  
}  }

public static void main(String[] args)  throws Exception 
{
//SUCK IT UP AND DO IT ALRIGHT
//scan=new FastReader("input.txt");
//out = new PrintWriter ("output.txt");
   // System.out.println(pow((long)1e9,(long)1e9));
  int n=scan.nextInt();
  int arr[]=new int[n];
  for(int i=0;i<n;i++)
    arr[i]=scan.nextInt();
//Arrays.sort(arr);
/*int pos1=1,pos2=(int)1e6;
int res1=(int)1e9,res2=0;
int cnt1=0,cnt2=0;
for(int i=0;i<n;i++)
{
    int d1=Math.abs(arr[i]-1);
    int d2=Math.abs(arr[i+1]-pos2);
    res1=Math.min(res1,Math.max(d1,d2));
    
}
out.println(res1);*/
int i=1,j=(int)1e6;
int pos1=1,pos2=(int)1e6;
int k=0;
int sec=(int)1e6+5;
while(i<j)
{
     if(k==n)
        break;
    if(i==arr[k]||j==arr[k]){
        sec=Math.min(sec,Math.max(pos2-arr[k],arr[k]-pos1));
        k++;
    }
   // out.println(i);
   
i++;
j--;

}
out.println((int)1e6-sec-1);
out.close();

//SEE UP 

}
static long binexp(long a,long n)
{
    if(n==0)
        return 1;
    long res=binexp(a,n/2);
    if(n%2==1)
        return res*res*a;
    else 
        return res*res;
}
static long powMod(long base, long exp, long mod) {
       if (base == 0 || base == 1) return base;
       if (exp == 0) return 1;
       if (exp == 1) return base % mod;
       long R = powMod(base, exp/2, mod) % mod;
       R *= R;
       R %= mod;
       if ((exp & 1) == 1) {
           return base * R % mod;
       }
       else return R % mod;
   }
static double dis(double x1,double y1,double x2,double y2)
{
    return Math.sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
}
static long mod(long x,long y)
    {
        if(x<0)
            x=x+(-x/y+1)*y;
        return x%y;
    }
 public static  long pow(long b, long e) {
            long r = 1;
            while (e > 0) {
                if (e % 2 == 1) r = r * b ;
                b = b * b;
                e >>= 1;
            }
            return r;
        }
private static void sort(long[] arr) {
        List<Long> list = new ArrayList<>();
        for (long object : arr) list.add(object);
        Collections.sort(list);
        for (int i = 0; i < list.size(); ++i) arr[i] = list.get(i);
    }
 public static class FastReader {
        BufferedReader br;
        StringTokenizer root;
        
 
        public FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
        FastReader(String filename)throws Exception
        {

            br=new BufferedReader(new FileReader(filename));
        }

        boolean hasNext(){
            String line;
            while(root.hasMoreTokens())
                return true;
            return false;
        }
 
        String next() {
            while (root == null || !root.hasMoreTokens()) {
                try {
                    root = new StringTokenizer(br.readLine());
                } catch (Exception addd) {
                    addd.printStackTrace();
                }
            }
            return root.nextToken();
        }
 
        int nextInt() {
            return Integer.parseInt(next());
        }
 
        double nextDouble() {
            return Double.parseDouble(next());
        }
 
        long nextLong() {
            return Long.parseLong(next());
        }
 
        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (Exception addd) {
                addd.printStackTrace();
            }
            return str;
        }
         public int[] nextIntArray(int arraySize) {
            int array[] = new int[arraySize];
 
            for (int i = 0; i < arraySize; i++) {
                array[i] = nextInt();
            }
 
            return array;
        }
}
 static class Pair implements Comparable<Pair>{
        public int x, y;
        public Pair(int x1, int y1) {
            x=x1;
            y=y1;
        }
        @Override
        public int hashCode() {
            return (int)(x + 31 * y);
        }
        public String toString() {
            return x + " " + y;
        }
        @Override
        public boolean equals(Object o){
            if (o == this) return true;
            if (o.getClass() != getClass()) return false;
            Pair t = (Pair)o;
            return t.x == x && t.y == y;
        }
public int compareTo(Pair o)
{
    return (x-o.x);

    }

static class pair{
    int i;
    int j;
pair(int i,int j){
    this.i=i;
    this.j=j;
}}}
 static class tuple{
        int x,y,z;
        tuple(int a,int b,int c){
            x=a;
            y=b;
            z=c;
        }
    }
    static class Edge{
        int d,w;
        Edge(int d,int w)
        {
            this.d=d;
            this.w=w;
        }
    }
}









