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

import static java.lang.Integer.compare;
import static java.lang.Math.*;
import static java.lang.System.in;
import static java.lang.System.out;
import static java.util.Arrays.deepToString;

/*
 *
 *16/2/18
 *8:38 PM
 *remedy441
 *
 */
public class CF938 {
    public static int mod = (int) (1e9 + 7);
    public static InputReader in;
    public static PrintWriter out;


    public static void solve() throws FileNotFoundException {

    	in = new InputReader(System.in);
    	out = new PrintWriter(System.out);
    	int n = in.ni();
    	int arx[] = in.nIArr(n);
    	int p1[] = new int[n];
    	int p2[] = new int[n];
    	p1[0] = arx[0]-1;
    	p2[0] = 1000000 - arx[n-1];
    	for(int i=1;i<n;i++){
    	    p1[i] = arx[i]-arx[i-1]+p1[i-1];
    	    p2[i] = arx[n-i]-arx[n-i-1]+p2[i-1];
        }
        //debug(p1,p2);
        long ans = Long.MAX_VALUE;
    	for(int i=0;i<n-1;i++){
    	    ans = Math.min(ans,Math.max(p1[i],p2[n-1-i-1]));
        }
        ans = Math.min(ans,Math.min(p1[n-1],p2[n-1]));
    	out.print(ans);
    	out.close();
    }
    public static void main(String[] args) {
    	new Thread(null, new Runnable() {
    		public void run() {
    			try {
    				solve();
    			} catch (Exception e) {
    				e.printStackTrace();
    			}
    		}
    	}, "1", 1 << 26).start();
    }

    static class Pair implements Comparable<Pair> {

    	int x, y, i;

    	Pair(int x, int y, int i) {
    		this.x = x;
    		this.y = y;
    		this.i = i;
    	}

    	Pair(int x, int y) {
    		this.x = x;
    		this.y = y;
    	}

    	public int compareTo(Pair o) {
    		if (this.x != o.x)
    			return compare(this.x, o.x);
    		else
    			return compare(this.y, o.y);
    		//return 0;
    	}

    	public boolean equals(Object o) {
    		if (o instanceof Pair) {
    			Pair p = (Pair) o;
    			return p.x == x && p.y == y && p.i == i;
    		}
    		return false;
    	}

    	public int hashCode() {
    		return new Integer(x).hashCode() * 31 + new Integer(y).hashCode() + new Integer(i).hashCode() * 37;
    	}

    }

    public static long add(long a, long b) {
    	long x = (a + b);
    	while (x >= mod)
    		x -= mod;
    	return x;
    }

    public static long sub(long a, long b) {
    	long x = (a - b);
    	while (x < 0)
    		x += mod;
    	return x;
    }

    public static long mul(long a, long b) {
    	long x = (a * b);
    	while (x >= mod)
    		x -= mod;
    	return x;
    }

    public static boolean isPal(String s) {
    	for (int i = 0, j = s.length() - 1; i <= j; i++, j--) {
    		if (s.charAt(i) != s.charAt(j))
    			return false;
    	}
    	return true;
    }

    public static String rev(String s) {
    	StringBuilder sb = new StringBuilder(s);
    	sb.reverse();
    	return sb.toString();
    }

    public static long gcd(long x, long y) {
    	if (x % y == 0)
    		return y;
    	else
    		return gcd(y, x % y);
    }

    public static int gcd(int x, int y) {
    	if (x % y == 0)
    		return y;
    	else
    		return gcd(y, x % y);
    }

    static int modInverse(int a, int m) {
    	int m0 = m, t, q;
    	int x0 = 0, x1 = 1;
    	if (m == 1)
    		return 0;
    	while (a > 1) {
    		// q is quotient
    		q = a / m;
    		t = m;
    		// m is remainder now, process same as
    		// Euclid's algo
    		m = a % m;
    		a = t;
    		t = x0;
    		x0 = x1 - q * x0;
    		x1 = t;
    	}
    	// Make x1 positive
    	if (x1 < 0)
    		x1 += m0;
    	return x1;
    }

    public static long gcdExtended(long a, long b, long[] x) {

    	if (a == 0) {
    		x[0] = 0;
    		x[1] = 1;
    		return b;
    	}
    	long[] y = new long[2];
    	long gcd = gcdExtended(b % a, a, y);

    	x[0] = y[1] - (b / a) * y[0];
    	x[1] = y[0];

    	return gcd;
    }

    public static long mulmod(long a, long b, long m) {
    	if (m <= 1000000009)
    		return a * b % m;

    	long res = 0;
    	while (a > 0) {
    		if ((a & 1) != 0) {
    			res += b;
    			if (res >= m)
    				res -= m;
    		}
    		a >>= 1;
    		b <<= 1;
    		if (b >= m)
    			b -= m;
    	}
    	return res;
    }

    public static int abs(int a, int b) {
    	return (int) Math.abs(a - b);
    }

    public static long abs(long a, long b) {
    	return (long) Math.abs(a - b);
    }

    public static int max(int a, int b) {
    	if (a > b)
    		return a;
    	else
    		return b;
    }

    public static int min(int a, int b) {
    	if (a > b)
    		return b;
    	else
    		return a;
    }

    public static long max(long a, long b) {
    	if (a > b)
    		return a;
    	else
    		return b;
    }

    public static long min(long a, long b) {
    	if (a > b)
    		return b;
    	else
    		return a;
    }

    public static long pow(long n, long p, long m) {
    	long result = 1;
    	if (p == 0)
    		return 1;
    	if (p == 1)
    		return n;
    	while (p != 0) {
    		if (p % 2 == 1)
    			result *= n;
    		if (result >= m)
    			result %= m;
    		p >>= 1;
    		n *= n;
    		if (n >= m)
    			n %= m;
    	}
    	return result;
    }

    public static long pow(long n, long p) {
    	long result = 1;
    	if (p == 0)
    		return 1;
    	if (p == 1)
    		return n;
    	while (p != 0) {
    		if (p % 2 == 1)
    			result *= n;
    		p >>= 1;
    		n *= n;
    	}
    	return result;
    }

    public static void debug(Object... o) {
    	System.out.println(deepToString(o));
    }

    static class InputReader {
    	private final InputStream stream;
    	private final byte[] buf = new byte[8192];
    	private int curChar, snumChars;
    	private SpaceCharFilter filter;

    	public InputReader(InputStream stream) {
    		this.stream = stream;
    	}

    	public int snext() {
    		if (snumChars == -1)
    			throw new InputMismatchException();
    		if (curChar >= snumChars) {
    			curChar = 0;
    			try {
    				snumChars = stream.read(buf);
    			} catch (IOException e) {
    				throw new InputMismatchException();
    			}
    			if (snumChars <= 0)
    				return -1;
    		}
    		return buf[curChar++];
    	}

    	public int ni() {
    		int c = snext();
    		while (isSpaceChar(c)) {
    			c = snext();
    		}
    		int sgn = 1;
    		if (c == '-') {
    			sgn = -1;
    			c = snext();
    		}
    		int res = 0;
    		do {
    			if (c < '0' || c > '9')
    				throw new InputMismatchException();
    			res *= 10;
    			res += c - '0';
    			c = snext();
    		} while (!isSpaceChar(c));
    		return res * sgn;
    	}

    	public long nl() {
    		int c = snext();
    		while (isSpaceChar(c)) {
    			c = snext();
    		}
    		int sgn = 1;
    		if (c == '-') {
    			sgn = -1;
    			c = snext();
    		}
    		long res = 0;
    		do {
    			if (c < '0' || c > '9')
    				throw new InputMismatchException();
    			res *= 10;
    			res += c - '0';
    			c = snext();
    		} while (!isSpaceChar(c));
    		return res * sgn;
    	}

    	public int[] nIArr(int n) {
    		int a[] = new int[n];
    		for (int i = 0; i < n; i++) {
    			a[i] = ni();
    		}
    		return a;
    	}

    	public long[] nLArr(int n) {
    		long a[] = new long[n];
    		for (int i = 0; i < n; i++) {
    			a[i] = nl();
    		}
    		return a;
    	}

    	public String readString() {
    		int c = snext();
    		while (isSpaceChar(c)) {
    			c = snext();
    		}
    		StringBuilder res = new StringBuilder();
    		do {
    			res.appendCodePoint(c);
    			c = snext();
    		} while (!isSpaceChar(c));
    		return res.toString();
    	}

    	public String nextLine() {
    		int c = snext();
    		while (isSpaceChar(c))
    			c = snext();
    		StringBuilder res = new StringBuilder();
    		do {
    			res.appendCodePoint(c);
    			c = snext();
    		} while (!isEndOfLine(c));
    		return res.toString();
    	}

    	public boolean isSpaceChar(int c) {
    		if (filter != null)
    			return filter.isSpaceChar(c);
    		return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    	}

    	private boolean isEndOfLine(int c) {
    		return c == '\n' || c == '\r' || c == -1;
    	}

    	public interface SpaceCharFilter {
    		public boolean isSpaceChar(int ch);
    	}

    }

}
