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.
#include <bits/stdc++.h>
using namespace std;
template <class T>
inline T sqr(const T &x) {
  return x * x;
}
inline long long sqr(int x) { return sqr<long long>(x); }
template <class T>
T binpow(const T &a, long long n) {
  return n == 0 ? 1 : sqr(binpow(a, n / 2)) * (n % 2 ? a : 1);
}
long long binpow(long long a, long long n, long long modulo) {
  return n == 0 ? 1
                : sqr(binpow(a, n / 2, modulo)) % modulo * (n % 2 ? a : 1) %
                      modulo;
}
long long gcd(long long a, long long b, long long &x, long long &y) {
  if (a == 0) {
    x = 0;
    y = 1;
    return b;
  }
  long long x1, y1;
  long long d = gcd(b % a, a, x1, y1);
  x = y1 - (b / a) * x1;
  y = x1;
  return d;
}
inline long long phi(long long n) {
  long long result = n;
  for (long long i = 2; i * i <= n; ++i)
    if (n % i == 0) {
      while (n % i == 0) n /= i;
      result -= result / i;
    }
  if (n > 1) result -= result / n;
  return result;
}
inline vector<long long> inverseAll(long long m) {
  vector<long long> r(m);
  r[1] = 1;
  for (int i = 2; i < m; ++i) r[i] = (m - (m / i) * r[m % i] % m) % m;
  return r;
}
inline long long gcd(long long a, long long b) { return gcd(a, b, a, b); }
inline long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
inline long long llrand() {
  const long long lsbToFill = (sizeof(long long) << 3) - 1;
  const long long bitsFilledInIteration = __builtin_popcountll(RAND_MAX);
  long long number = 0;
  for (long long lsbFilled = 0; lsbFilled <= lsbToFill;
       lsbFilled += bitsFilledInIteration) {
    number ^= (((long long)rand()) << lsbFilled);
  }
  return number & numeric_limits<long long>::max();
}
inline long long llrand(long long begin, long long end) {
  return begin + llrand() % (end - begin);
}
struct Dinic {
  struct Edge {
    int u, v;
    long long cap, flow;
    Edge() {}
    Edge(int u, int v, long long cap) : u(u), v(v), cap(cap), flow(0) {}
  };
  int N;
  vector<Edge> E;
  vector<vector<int>> g;
  vector<int> d, pt;
  Dinic(int N) : N(N), E(0), g(N), d(N), pt(N) {}
  void AddEdge(int u, int v, long long cap) {
    if (u != v) {
      E.emplace_back(Edge(u, v, cap));
      g[u].emplace_back(E.size() - 1);
      E.emplace_back(Edge(v, u, 0));
      g[v].emplace_back(E.size() - 1);
    }
  }
  bool BFS(int S, int T) {
    queue<int> q({S});
    fill(d.begin(), d.end(), N + 1);
    d[S] = 0;
    while (!q.empty()) {
      int u = q.front();
      q.pop();
      if (u == T) break;
      for (int k : g[u]) {
        Edge &e = E[k];
        if (e.flow < e.cap && d[e.v] > d[e.u] + 1) {
          d[e.v] = d[e.u] + 1;
          q.emplace(e.v);
        }
      }
    }
    return d[T] != N + 1;
  }
  long long DFS(int u, int T, long long flow = -1) {
    if (u == T || flow == 0) return flow;
    for (int &i = pt[u]; i < g[u].size(); ++i) {
      Edge &e = E[g[u][i]];
      Edge &oe = E[g[u][i] ^ 1];
      if (d[e.v] == d[e.u] + 1) {
        long long amt = e.cap - e.flow;
        if (flow != -1 && amt > flow) amt = flow;
        if (long long pushed = DFS(e.v, T, amt)) {
          e.flow += pushed;
          oe.flow -= pushed;
          return pushed;
        }
      }
    }
    return 0;
  }
  long long MaxFlow(int S, int T) {
    long long total = 0;
    while (BFS(S, T)) {
      fill(pt.begin(), pt.end(), 0);
      while (long long flow = DFS(S, T)) total += flow;
    }
    return total;
  }
};
vector<long long> Dijkstra(const vector<list<pair<int, long long>>> &g, int s) {
  vector<long long> d(int((g).size()), numeric_limits<long long>::max() / 2LL);
  priority_queue<pair<long long, int>> q;
  d[s] = 0;
  q.emplace(-0, s);
  while (!q.empty()) {
    while (q.top().first > d[q.top().second]) {
      q.pop();
    }
    int v = q.top().second;
    q.pop();
    for (const auto &cw : g[v]) {
      if (d[v] + cw.second < d[cw.first]) {
        d[cw.first] = d[v] + cw.second;
        q.emplace(-d[cw.first], cw.first);
      }
    }
  }
  return d;
}
struct BinarySearchIterator
    : public std::iterator<std::forward_iterator_tag, bool> {
  long long value;
  typename iterator_traits<BinarySearchIterator>::difference_type operator-(
      const BinarySearchIterator &it) const {
    return value - it.value;
  }
  BinarySearchIterator &operator++() {
    ++value;
    return *this;
  }
  bool operator!=(const BinarySearchIterator &it) const {
    return value != it.value;
  }
  bool operator*() const { return true; }
};
template <int ALPHA>
class AhoCorasick {
 public:
  static const int ILLEGAL_INDEX;
  static const int ROOT;
  struct Node {
    bool leaf;
    int parent;
    int parentCharacter;
    int link;
    int next[ALPHA];
    int go[ALPHA];
    int outputFunction;
    Node(int parent = ILLEGAL_INDEX, int parentCharacter = ALPHA)
        : leaf(false),
          parent(parent),
          parentCharacter(parentCharacter),
          link(ILLEGAL_INDEX),
          outputFunction(ILLEGAL_INDEX) {
      fill_n(next, ALPHA, ILLEGAL_INDEX);
      fill_n(go, ALPHA, ILLEGAL_INDEX);
    }
  };
  vector<Node> tree = vector<Node>(1);
  AhoCorasick() {}
  AhoCorasick(int maxStatesNumber) { tree.reserve(maxStatesNumber); }
  template <class Iterator>
  void add(int length, const Iterator begin) {
    int vertex = ROOT;
    for (int i = 0; i < length; ++i) {
      if (ILLEGAL_INDEX == tree[vertex].next[begin[i]]) {
        tree[vertex].next[begin[i]] = int((tree).size());
        tree.push_back(Node(vertex, begin[i]));
      }
      vertex = tree[vertex].next[begin[i]];
    }
    tree[vertex].leaf = true;
  }
  int getLink(int vertex) {
    assert(0 <= vertex && vertex < tree.size());
    if (ILLEGAL_INDEX == tree[vertex].link) {
      if (ROOT == vertex || ROOT == tree[vertex].parent) {
        tree[vertex].link = ROOT;
      } else {
        tree[vertex].link =
            go(getLink(tree[vertex].parent), tree[vertex].parentCharacter);
      }
    }
    return tree[vertex].link;
  }
  int go(int vertex, int character) {
    assert(0 <= character && character < ALPHA);
    assert(0 <= vertex && vertex < tree.size());
    if (ILLEGAL_INDEX == tree[vertex].go[character]) {
      if (ILLEGAL_INDEX == tree[vertex].next[character]) {
        tree[vertex].go[character] =
            ROOT == vertex ? ROOT : go(getLink(vertex), character);
      } else {
        tree[vertex].go[character] = tree[vertex].next[character];
      }
    }
    return tree[vertex].go[character];
  }
  int getOutputFunction(int vertex) {
    assert(0 <= vertex && vertex < tree.size());
    if (ILLEGAL_INDEX == tree[vertex].outputFunction) {
      if (tree[vertex].leaf || ROOT == vertex) {
        tree[vertex].outputFunction = vertex;
      } else {
        tree[vertex].outputFunction = getOutputFunction(getLink(vertex));
      }
    }
    return tree[vertex].outputFunction;
  }
};
template <int ALPHA>
const int AhoCorasick<ALPHA>::ILLEGAL_INDEX = -1;
template <int ALPHA>
const int AhoCorasick<ALPHA>::ROOT = 0;
int main(int argc, const char *argv[]) {
  ios::sync_with_stdio(false);
  cin.tie(0);
  srand((unsigned int)time(NULL));
  int n;
  while (cin >> n) {
    vector<int> a(n);
    for (int i = (0); i < (n); ++i) {
      cin >> a[i];
    }
    int answer = min(a[n - 1] - 1, (int)1e6 - a[0]);
    for (int i = (0); i < (n - 1); ++i) {
      answer = min(answer, max((int)1e6 - a[i + 1], a[i] - 1));
    }
    cout << answer << endl;
  }
  return 0;
}
